Information and Practices on Shore Scuba Diving

Shore scuba diving is usually less expensive and requires less logistics than scuba diving from a boat. The main consideration for shore scuba diving is the right tide and a good scuba dive buddy. For a scuba diver intending to go shore scuba diving, there are a number of matters to consider.

Entry and exit are covered in Suite 101 article: Entry and Exit for Shore Scuba Diving.

Currents at a Shore Scuba Dive Site

Currents, or movement of water, at a shore scuba dive site can have a different impact than when diving from a boat. Entry and exit are the main issues that are impacted by current at a scuba dive site.

With a boat dive, if a scuba diver is swept away by currents at a scuba dive site, the dive boat can motor over and pick up the missing scuba diver. However, at a shore scuba dive site if a diver is swept away by currents, then the diver may need to consider an alternate exit point.

When underwater, currents at a scuba dive site can have an impact on the dive. For example, diving under surf can result in the diver moving up and down with the swells. This can be cause feelings of anxiety with some divers as there is a feeling of loss of control.

Composition of the Bottom at a Shore Scuba Dive Site

At a shore scuba dive site, the diver needs to be aware of the composition of the bottom. There could be hazards for scuba divers:

•Submerged rocks and trees that could lead to divers falling, or getting bits of equipment snagged.
•Mud can lead bad silting problems, or a scuba diver sinking into the mud.
•Rubbish such as broken bottles, bits of timber or metal can cut diver’s equipment or their skin.
Topography of the Bottom at a Shore Scuba Dive Site

A scuba diver needs to be aware of the topography of the bottom at a shore scuba dive site. For example there might just be a gentle slope from the entry point or it may be a large drop-off. Trenches, caves, sandbars, holes, cliffs can all present unknown challenges for a scuba diver.

Marine Life at a Shore Scuba Dive Site

Marine life at a shore scuba dive site can present some unique challenges. The initial consideration must be the entry and exits points, as the following can present difficulties getting in and out of the water:

•coral
•moss
•seaweed
•oysters and barnacles
•a grassy edge.
Marine stingers like box jellyfish, stinging hydra, fish with sharp spines may have to be dealt with at the entry and exit points. Under the water there can be things like large seaweed like kelp growing near the shore that can present an entanglement risk.

Some great dives can be experienced when going shore scuba diving. There are many interesting things to see and discover around the rocky headlands, river mouths, coral reefs and jetties of the ocean.

The Backward Roll Scuba Entry From a Scuba Boat Read more at Suite101: The Backward Roll Scuba Entry From a Scuba Boat

There are two main ways for a scuba diver to enter the water from a scuba dive boat:

1.The scuba giant stride entry.
2.The backward roll scuba entry.
The scuba giant stride entry is the safest and most common method of getting into the water. This is used when there is a secure platform from which to simply step off.

The scuba backward roll can be used when the scuba dive boat doesn’t have a swim deck, or ladder.

Prepare for the Backward Roll Scuba Entry

First stage of a successful backward roll scuba entry is:

•All equipment should be together.
•Know the location of the boat exit point
•Know who the dive buddy will be.
•Know what to do and where to go after entering the water. This could be to wait for the buddy; or remainder of dive group. Maybe swim for the anchor; or the trailing line out the back of the boat.
Get Into Position for the Scuba Backward Roll Entry

After getting prepared, the scuba diver must get into position for the backward roll scuba entry:

•Put on final pieces of scuba equipment.
•Sit on the side of boat with the tank supported on the side of the boat.
•All pieces of equipment should be securely fastened, or in pockets of the buoyancy compensator.
•Gauges and second stage should be sitting in the lap.
•Mask should be on, rinsed and cleaned. If possible by turning around and getting a mask full of water. If not, it should be done when in the water.
•Check all clear around – no-one standing on fins.
•Do a buddy-check – check buddy’s air is on, etc.
Get Steady for the Backward Roll Scuba Entry

Just prior to doing the backward roll scuba entry:

•Inflate the buoyancy compensator, just enough to be neutrally buoyant. But not too full so it could force against the water and smash the tank against the back of the head.
•Check any divers in the water behind have moved away. Check nothing else in the water, like a rope or dive flag. Check over both shoulders.
•Place the tank over the side of the boat, the weight being taken by the buoyancy compensator.
•Left hand holds gauges in lap, while the palm of the right hand holds the second stage eof the regulator in the mouth, with the fingers holding the mask.
Doing the Backward Roll Scuba Entry

The divemaster may count in the divers.

One last check behind; lift the legs and let the tank’s weight take the diver into the water. The tank should break the water.

The scuba diver may do a 360-degree roll, or simply drop down a few feet.

At this point the scuba diver should not panic. The buoyancy compensator should bring the diver back to the surface.

Check After Doing the Scuba Backward Roll Entry

Once back on the surface, another quick check of equipment needs to be done.

Especially important is the mask as the strap at the back of the head may have shifted from the force of the entry.

A quick signal to the divemaster on the boat that everything is OK, wait for the buddy or the rest of the dive team. Then head off for the dive.

The backward roll scuba entry is an easy way to get in the water. The main thing is not to be too concerned with the roll in the water. With the mask on and regulator in the mouth there is no problem with water getting into the nose of taking a mouthful of water.

Equipment can Affect Scuba Diver Air Consumption

Having well maintained and functioning equipment is one of the best ways to reduce air consumption when scuba diving. From leaking hoses, to inefficient regulators and problems with the buoyancy compensator, there are a myriad of ways in which equipment can lead to increased air consumption.

Streamline Scuba Equipment to Conserve Air

In the quest to conserve air when underwater on scuba, the diver’s equipment should be streamlined. Being streamlined prevents less drag in the water which has to be overcome by using more energy.

All scuba equipment should be as tight fitting and comfortable as possible.

Hose and straps should be arranged in such a way so they aren’t hanging down and causing drag, getting caught on bits of coral or rocks, or even dragging in the sand.

Bits and pieces like torches, knives, and gauges should be placed in pockets to reduce drag.

Scuba Equipment Should be Working Efficiently to Conserve Air

All equipment should be checked and serviced to ensure it is working correctly. There shouldn’t be any of those little streams of silvery bubbles rising to the surface that are a common site on most dives. These are a tell-tale sign of air being wasted.

The scuba regulator should be serviced regularly and well tuned. An efficient regulator working properly will deliver the correct amount of air. If a scuba diver needs to drag at the mouthpiece to get a lungful of air, then air is being wasted.

Hoses shouldn’t leak. The most common point for hoses to leak are at the swivel joints such as gauges or at the second stage connection. If there is a small stream of bubble from these places, then the hose needs to be replaced or repaired. This is not just to conserve air, but also for safety as a leak is a direct indication that something is wrong, and a catastrophic failure could be close.

The scuba face mask should be a tight fit that doesn’t allow water to seep in. If a scuba diver has to be continually clearing the mask of water during a dive, this simply wastes air.

Poorly fitted fins do not provide the optimum efficiency and lead to increased air consumption.

Buoyancy Compensator is a Main Source of Reduced Scuba Air Consumption

The buoyancy compensator shouldn’t leak. There are a number of places where air can escape from a buoyancy compensator, such as the dump valves; or maybe small holes in the bladder.

The buoyancy compensator power inflator should be regularly checked. It should be a good, tight fit when connected.

The oral inflator is a common place for leaks as a small piece of sand or foreign material can get caught in the mechanism and hold it open. This can create two problems when looking at air consumption. The air in the buoyancy compensator could escape, or water could get. Both these will lead to the buoyancy compensator needing to be regularly topped up during a scuba dive.

Keep Warm to Conserve Air When Scuba Diving

Heat lost from the body is energy, and part of the energy used on a dive comes from air from the scuba tank. Therefore, the warmer a diver is on a scuba dive, the less air should be used.

However, the selection of a suitable wetsuit needs to consider other issues that could lead to increased air consumption, That is, if it is too tight it will restrict movement causing the diver to work harder, which will lead to increased air consumption.

To help in the continual battle to improve air consumption while scuba diving, equipment is one area to investigate to get a few more minutes underwater.

Other areas to look at in decreasing air consumption while scuba diving are scuba techniques and the human factor.

Ways Scuba Divers Can Conserve Air Scuba Diving

For a safe, enjoyable scuba dive, a diver should work on not wasting precious air from the scuba tank.

Breathe Slow and Deeply to Conserve Scuba Air

One of the best ways for a scuba diver to conserve air scuba diving is to breathe properly on scuba equipment. It seems strange as breathing is a natural instinct, but breathing when underwater on scuba needs to be controlled.

The breathing needs to be slow, regular and deep enough to fill the lungs. This type of slow breathing allows the body to absorb enough oxygen.

Breaths should be not too deep, but just comfortable. Taking huge drafts of air from the regulator can lead to hyperventilation problems.

Short, shallow breaths are usually the symptom of an anxious diver. This type of breathing doesn’t allow enough oxygen to be absorbed into the body’s cells and can exacerbate the anxiety cycle.

Slow Down on the Scuba Dive to Conserve Air

Scuba diving is not a competition. There is nothing to gain from being the diver who covers the most amount of ground underwater. The only healthy competition between scuba divers should be who comes up with the most air in the tank after the dive. Winning this competition can be assisted by taking a slow, relaxed approach to each dive.

Use the Environment to Assist Moving Underwater to Conserve Air

The environment should be used to advantage to move around underwater. The scuba dive plan should use the current to the best advantage. That is, consider the direction of the current and address the decision which way to go first.

The current should be used to move wherever possible; rather than trying to swim against it. In some situations with a reasonably strong current flowing, it may be possible for a diver with good buoyancy skills to hang upright in the water and let the current take them along for the ride.

In some dive sites, such as close in to a small island, the ocean swells may impact on the diver underwater. In this situation, the scuba diver should use the swells by only swimming when the waves are in the right direction; stop when the wave recedes and then swim forward again on the next swell.

To Conserve Air, Get Scuba Dive Fit out of the Water

There are many advantages in getting scuba dive fit out of the water.

It would be expected that a fit and healthy diver is more efficient than an unhealthy diver. And therefore would use less oxygen. Even if this assumption wasn’t true, there are the many other well know reasons for getting, and keeping, fit and healthy.

When out of the water, scuba divers should concentrate on techniques to improve breathing. Yoga, relaxing breathing techniques, and focussing on stress reduction out of the water can all improve a scuba diver’s air consumption. Anything to make a relaxed, easy breathing diver.

Aerobic exercise when not scuba diving that works the heart and lungs will build strength in these areas that will improve air conservation while underwater.

Possibly the best way to address the human elements of improving air consumption is by simply diving regularly. Regular scuba diving will build “dive fitness” with accompanying decrease in air consumption.

Other areas to look at in decreasing air consumption while scuba diving are scuba diving techniques and equipment issues.

Different Types of Recreational Scuba Diving

The following is a brief summary of just some of the areas in which a recreational scuba diver can explore the underwater world.

Coral Reef Scuba Diving

One of the most enjoyable aspects of scuba diving can be a relaxing scuba dive over a coral reef. If the conditions are right, a scuba diver can see a magnificent vista all around.

Fish life coming and exploring the scuba diver, majestic fish like manta rays, huge wrasse and groper. Turtles, non-threatening sharks and tiny fish like the famous Nemo clown fish can all be seen on a coral reef dive.

Coral reef scuba diving is usually safe in that most of the marine life and colour is experienced in just thirty feet of depth. Shore scuba diving off places like Lady Elliot Island on Australia’s Great Barrier Reef is a great place to experience the unique aspects of coral reef scuba diving.

Exploring Sunken Wrecks Scuba Diving

Exploring sunken wrecks can be an exciting and challenging underwater activity.

In the South Pacific there are a large number of sunken wrecks from World War Two. One of the most famous is the wreck of the President Coolidge, a sunken ocean liner in the harbour at Santo in Vanuatu.

Wreck diving has risks in that a recreational scuba diver is swimming inside a sunken vessel. It can be dark, cramped and it is possible to get lost inside. So precautions like a divemaster guide and safety lines may be needed.

Another problem with scuba diving on wrecks is that many are usually in deep water requiring decompression to ensure divers don’t get the Bends. However, this type of recreational scuba diving can provide a huge adrenalin hit when a diver surfaces after exploring within the bowels of a sunken ship.

Scuba Dive Travel Trips

Scuba diving can open up the world by providing a focus on a holiday. Organising the trip, packing the scuba equipment, then heading off to some exotic location in a far part of the world to get wet underwater makes for a great holiday.

For example, a recreational scuba dive trip can combine the above relaxing coral reef diving and challenging wreck diving. This type of scuba holiday can be had at some remote locations like Truk Lagoon in Micronesia.

It is reputed that some of the best coral reef scuba diving in the world is in places like the Maldives in the Indian Ocean, the Red Sea off Egypt and on Australia's Great Barrier Reef.

Cave Scuba Diving

Like wreck diving, cave scuba diving can be an exciting and challenging underwater activity for a recreational scuba diving. Slipping into the dark waters of a cave can be a solid adrenalin hit.

And as with wreck diving, there are a range of dives that a recreational scuba diver can undertake. From deep, dark diving (after an intensive training course) in Australia’s Cocklebiddy Caves on the desert of the Nullabor Plain; to an easy dive in the Grotto de la Troisieme, a freshwater cave in New Caledonia.

Just Being Underwater

For every type of diving a recreational scuba diver wants to undertake; there are a number of scuba divers who simply enjoy the thrill of breathing underwater. That is, being at one with the fish and underwater landscape.

Whether cave diving, exploring wrecks or simply getting wet at a local scuba dive site, it is a unique experience to strap on a scuba tank and drop into the fascinating “inner space” of the underwater world.

Tangalooma Wrecks Scuba Dive Site

Some novice divers get the Tangalooma Wrecks confused with the Curtin Artificial Reef.

These are two separate artificial reefs on the western side of Moreton Island. The Tangalooma Wrecks are just north of the Tangalooma Island Resort and can be seen above the waterline. While the Curtin Artificial Reef can not be seen above the water and is about seven kilometres to the north.

History of the Tangalooma Wrecks Artificial Reef

The Tangalooma Wrecks Artificial Reef was started in 1963 when a group of recreational boat owners lobbied the government for an artificial harbour to be built on the western side of Moreton Island.

The result was around 15 de-commissioned steam driven dredges and barges sunk on a sandbank about 500 metres off the beach.

Location of the Tangalooma Wrecks Artificial Reef

The Tangalooma Wrecks are only a short walk along the beach north of the Tangalooma Island Resort. This resort was once the site of the Tangalooma Whaling Station.

The reef is easy to see, with the twisted mass of metal, old dredges and funnels poking out of the water.

The GPS coordinates for the Tangalooma Wrecks Reef are:

-27.163202 153.368669

What’s at the Tangalooma Wrecks Artificial Reef Scuba Dive Site

The Tangalooma Wrecks Artificial Reef scuba dive site is a shallow scuba dive, with a maximum depth of only 10 metres. This makes it a good location for introductory scuba dives. Many scuba instructors use this site as an introduction to open water scuba diving for students working towards their open water diving certification.

There are some penetration dives on the wrecks. These should only be attempted with a scuba divemaster or scuba instructor who is well acquainted with the wrecks.

Fish Life at the Tangalooma Wrecks Artificial Reef

Apart from the excitement of scuba diving on sunken wrecks, the Tangalooma Wrecks offers a prolific display of marine life.

Before the artificial reef was formed, the area was basically a marine desert. A flat, sandy bottom didn’t provide much in the way of marine habitats. However, now with the abundance of nooks and crannies, and a place for soft corals and seaweeds to grow, the reef teems with life.

There are a myriad of tropical fish, placid wobbegong sharks, schools of trevally, with soft corals over the sunken bits of the wrecks.

Scuba Dive Plan for the Tangalooma Wrecks

Best time to scuba dive the Tangalooma Wrecks is either side of the high tide, so that the change of tide is in the middle of the dive. Divers need to carefully plan around the tides as the currents can be quite strong.

A good scuba dive plan for the Tangalooma Wrecks is a drift dive. However, this must be carefully planned so the currents are not too strong. The boat needs to be well coordinated, especially with the pick-up at the end of the dive.

Snorkelling at the Tangalooma Wrecks

With the Tangalooma Wrecks being in such shallow water makes it a great place for snorkelling.

There are a few things to be aware of when snorkelling at the Tangalooma Wrecks.

Stingers, like fire coral or stinging hydra, can give a snorkeller a painful rash. Stonefish with their poisonousness barbs can be a threat if accidentally stood on.

Sharing the Tangalooma Wrecks Dive Site With Fishermen

With the reef attracting so much fishlife, the reef is a magnet for fishermen. And therefore scuba divers and snorkellers must share the site.

The main risk when underwater is the possibility of getting tangled in some old fishing lines that hang around the wrecks. A dive knife should be carried when diving or snorkelling at the Tangalooma Wrecks.

As the Tangalooma Wrecks form a harbour, there is a large number of boat movements in the area. A scuba diver or snorkeller needs to be extra vigilant; especially after a drift dive.

The Tangalooma Wrecks Dive Site is a fascinating spot for a scuba dive or for snorkelling. Sunken wrecks, prolific marine life in a shallow, easily accessible location make it a dive site that offers a lot for a scuba diver or snorkeller.

Curtin Artificial Reef Scuba Dive Site, Brisbane

Curtin Artificial Reef off the east coast of Australia comprises about 20 wrecks, all offering an interesting scuba dive. There are couple of whale chasers left over from the Tangalooma Whaling Station, a number of barges and even an old Brisbane tram.

History of the Curtin Artificial Reef

The Curtin Artificial Reef started in 1968 when the Underwater Research Group of Queensland (URGQ) obtained approval to form an artificial reef in Moreton Bay. The first item to be placed on the reef was a gravel barge.

Frank Curtin, a member of the Underwater Research Group of Queensland, was the main driver behind the formation of the artificial reef and so the reef was named in his honour.

Location of the Curtin Artificial Reef

The Curtin Artificial Reef is about seven kilometres north of the Tangalooma Island Resort; between the settlement of Bulwer and Cowan Cowan Point. The wrecks sit on the sandy bottom, though a number have been covered in the mud and sand that flows on the currents through the scuba dive site.

The Curtin Artificial Reef should not be confused with the Tangalooma Wrecks, that is an artificial breakwater about seven kilometres to the south.

The GPS coordinates for Curtin Artificial Reef are:

-27.11005 153.3625

When to Dive at Curtin Artificial Reef Scuba Dive Site

The best time to dive the Curtin Artificial Reef is either side of the high tide, so that the change of tide is in the middle of the dive. Divers need to carefully plan around the tides as the currents can be quite strong.

The URGQ recommends the optimum time to dive the Curtin Artificial Reef is when the high tide (recorded at the “Brisbane Bar”) is between 9.00 am and 11.00 am. This allows enough time either side of the high tide to get the best conditions.

On incoming tide the current runs north to south.

On the ebbing tide, the current runs south to north.

A drift dive can be a good dive plan, but must be carefully planned so the currents are not too strong. The boat needs to be well coordinated, especially with the pick-up at the end of the dive.

Scuba Dive Plan for the Curtin Artificial Reef Scuba Dive Site

There are some penetration dives possible; especially on the larger wrecks like the tug Melbourne that was sunk on the reef in 1979.

However, as with any penetration scuba diving on sunken wrecks, extreme care and rigorous dive planning is needed. A scuba divemaster with detailed knowledge of the wrecks should accompany any scuba diver wanting to do a penetration dive into the wrecks.

The Underwater Research Group of Queensland “recommends that none of the wrecks are penetrated.”

The tide and associated currents are a large factor in a scuba dive plan for the Curtin Artificial Reef. If a scuba diver does plan to penetrate into one of the wrecks the dive should be planned so it is done at the change of tide.

If possible, it can be a good idea to carry an underwater map of the Curtin Artificial Reef scuba dive site. A map is available from the URGQ website.

Fish Life at the Curtin Artificial Reef

Apart from the excitement of scuba diving on sunken wrecks, the Curtin Artificial Reef dive site offers a prolific display of marine life.

Before the artificial reef was formed, the area was basically a marine desert. A flat, sandy bottom didn’t provide much in the way of marine habitats. However, now with the abundance of nooks and crannies, and a place for soft corals and seaweeds to grow, the reef teems with life.

There are batfish, a myriad of tropical fish, gropers, placid wobbegong sharks, schools of trevally, various types of wrasse and the occasional rays.

Sharing the Curtin Artificial Reef Dive Site With Fishermen

With the reef attracting so much fishlife, the reef is a magnet for fishermen. And therefore scuba divers must share the site.

The main risk when underwater is the possibility of getting tangled up in some old fishing lines that hang around the wrecks. A dive knife should be carried when scuba diving the Curtin Artificial Reef.

There is also the risk of boats cruising around above, so a scuba diver needs to be extra vigilant on the ascent; especially after a drift dive.

And when underwater, a scuba diver needs to be wary of boats anchoring above. It’s not a good thing to be hit on the head by a wayward anchor while underwater at 20 metres.

The Curtin Artificial Reef Dive Site is a fascinating scuba dive. Sunken wrecks, prolific marine life, and challenges with currents make it a dive site that offers a lot for a scuba diver in the one dive.

Snorkeling, Exploring Another World

There is historic evidence that as far back as 3000 B.C., sponge divers practiced a form of snorkeling by using hollow reeds to help them breath when underwater.

Snorkeling is an inexpensive hobby requiring only a good quality eye mask, a snorkeling tube and swim fins to help navigate more quickly through the water.

Buying A Snorkeling Mask

The mask is one of the most important pieces of snorkeling equipment. It should fit snugly and comfortably on the face without leakage. It’s worthwhile to spend a little more money by going to a scuba or diving equipment store and having the mask professionally fitted.

The Snorkel, A Diver’s Breathing Tube

The snorkel provides the lifeline that allows divers to float face down in the water for extended periods of time. It consists of a flexible tube, usually made of plastic or rubber. The length of the snorkel tube varies between 12 and 18 inches. The length and bore, or diameter, of the tube depends on the size of the snorkeler. Larger people require more air and a longer tube with a wider bore will allow more air in and out of the tube.

The mouthpiece of the snorkel consists of two parts, a large, oval lip flange which fits inside the divers lips and the bite piece which is gripped between the teeth. The bite piece is to hold the snorkel in the mouth and should not be bitten too hard. The divers lips covering the flange provide the seal for the mouthpiece.

The top end of the snorkel should have some features to prevent water from coming in when waves splash over the top. Two of the most common are a simple ping-pong ball held in a tiny cage or diagonal plates, which allow water to flow in and out.

Finally, the snorkel should have an adjustable clip, about half way down the straight part of the tube, to attach the mask strap. The clip will hold the snorkel upright in the water and free up the diver’s hands for swimming.

Swim fins are an optional piece of snorkeling equipment, however, they do help to propel and manoeuvre the diver through the water more quickly. This is important when snorkeling in the Carribean and following that one elusive, multi-coloured fish dodging in and out of the coral reef. Most fins are adjustable, but make sure they are the right fit, not too loose or too tight.

Using the Snorkeling Equipment

For first time snorkelers, it’s a good idea to become comfortable wearing the mask and snorkel tube. Start in calm, shallow water by relaxing and breathing normally through the tube. Concentrate on watching the fish and viewing objects on the sea floor.

If the mask fogs up, use a little spit or mask defogger to clear the moisture and swish it around in the water before putting the mask back on.

Snorkeling can be a relaxing and exciting hobby, but some caution is advised:

•Do not snorkel, if you can’t swim
•Never snorkel alone, always have a swimming companion
•Stay away from areas with high boat, Jet Ski, surfing or water skiing traffic
•Raise a hand up out of the water before surfacing to make sure the area above is clear
•Do not step on or otherwise damage delicate coral reefs or underwater marine life
•Coral reefs have razor sharp edges, do not get to close
•If light-headedness or breathlessness occurs surface immediately and head for shore
•Wear a tee shirt or use a sun block with a high SPF on exposed areas of the body.
Snorkeling is an inexpensive and fun way to experience the incredible diversity of the undersea world. Floating freely above and among schools of brightly colored marine life can lift the soul and calm the mind.

Problems of Nitrogen Narcosis in Scuba Diving

The common term for nitrogen narcosis used in the scuba diving fraternity is the “raptures of the deep”. Another common term is a scuba diver suffering this condition is said to be “narked”.

What is Nitrogen Narcosis?

Nitrogen narcosis is a condition in scuba diving where a scuba diver has feelings of elation and euphoria. It is similar to being slightly intoxicated with alcohol, or from having nitrous oxide when undergoing certain medical procedures such as dental work.

Because of this impact of a scuba diver feeling invincible and reduced anxiety underwater, the condition has the potential to be extremely dangerous. Some divers have been known to take their regulator from their mouth; while other have lost all awareness of depth and simply continued swimming down to greater depths and into greater trouble.

Nitrogen narcosis usually occurs at depths greater than 30 metres. However, the condition can affect some scuba divers at a lesser depth.

The symptoms reduce as the diver ascends to shallower depths.

What Causes Nitrogen Narcosis?

Nitrogen narcosis is caused by the impact of nitrogen in the body.

A scuba diver breathes a normal mix of air from a scuba tank. This air contains around 79% nitrogen.

When breathed at depth the partial pressure of the nitrogen results in more nitrogen in the body. However, as nitrogen is an inert gas it doesn’t react with the body’s blood and tissues.

Because the nitrogen doesn’t react chemically with the body, it is considered that the nitrogen affects the signals that are sent along the nerve fibres in the body. This results in the impact being mainly related to brain and nerve functions.

Signs and Symptoms of Nitrogen Narcosis

Nitrogen narcosis affects scuba divers in different ways. The following are some of the reported signs and symptoms impacting the cognitive function of a scuba diver with nitrogen narcosis:

•General feelings of euphoria
•Feelings of elation
•A sense of well-being
•Over confidence
•Laughter
•Light-headedness
•Loss of decision making ability
•Memory problems.
Physical symptoms of a scuba diver with nitrogen narcosis can be:

•Vertigo
•Tunnel vision
•Impaired coordination and concentration
•Tingling or numbness in the body’s extremities.
The biggest problem with these symptoms is that a scuba diver suffering from some of the above symptoms of nitrogen narcosis may not be able to recognise that they have the symptom.

For example, a scuba diver suffering with a sensation of over-confidence and euphoria may not be able to think that there is something wrong because these are “good” type sensations. The loss of decision-making ability is obviously a serious problem if a scuba diver has to calculate decompression times underwater.

Problems can so easily occur when a scuba diver has these feelings of extreme confidence. They can go off and do things underwater that they wouldn’t normally do.

Scuba Diving’s Martini Law and Nitrogen Narcosis

In the diving fraternity, the impact of nitrogen narcosis in relation to depth is known as “Martini’s Law”. This is roughly based on the analogy that for each 10 metres in depth, the effect is like consuming one martini. At 30 metres, a scuba diver may feel like they have drunk three martinis.

This is a very rough guide only and should not be relied on to predict the onset of nitrogen narcosis

How Scuba Divers Can Prevent Nitrogen Narcosis

The onset of nitrogen narcosis is directly related to depth. The deeper the scuba diver goes, the greater the impact of nitrogen narcosis.

It is almost impossible to predict the depth that symptoms may start showing as nitrogen narcosis impacts each scuba diver differently. And the impact can vary from each scuba dive.

There are many variable such as cold, stress, fatigue. It is even thought that nitrogen narcosis may be worse depending on the amount of alcohol or some drugs that may have been taken into the body a few days earlier.

The best way to prevent nitrogen narcosis is to be aware of the possibility of narcosis occurring, and then if it does the scuba diver should immediately ascend to a shallower depth.

Scuba diving buddies should always be on the lookout for signs of nitrogen narcosis; especially on a deep dive over 25 metres.

The problem of nitrogen narcosis can best be addressed by the following:

•using a good scuba dive plan
•implementing good scuba diving practices
•keeping mentally and physically healthy
•a good relationship and understanding between scuba dive buddies
•keeping in shallow depths.
Nitrogen narcosis should not be something that is treated lightly, or considered a scuba diving myth. “Raptures of the Deep” is a true physiological problem that has the potential to be fatal for scuba divers.

Ear Injuries and Damage Caused by Scuba Diving

Damage to a scuba diver’s ears can be anything from an annoying case of swimmer’s ear or can be so significant the injury could result in permanent hearing loss.

Scuba Diving and Middle Ear Barotrauma

Trauma to the middle ear is one of the most common scuba diving injuries. It is called Barotitis Media and is usually caused by a middle ear squeeze.

If pressure in the middle ear is not equalised on descent, the body tries to equalise the inner ear by forcing fluid and blood into the middle ear cavity. This fluid is an attempt by the body to fill the inner ear cavity to reduce the pressure.

Middle ear barotrauma feels like a fullness in the ear. Hearing may be muffled, or there may even be complete hearing loss in the ear.

A scuba diver who believes they may have suffered middle ear barotrauma (Barotitis Media) during a scuba should seek treatment from a doctor.

Rupture of the Ear Drum During Scuba Diving

The ear drum is the thin membrane between the out ear canal and the middle ear. Its medical term is the tympanic membrane.

The ear drum prevents water and other foreign objects from getting into the middle ear.

The eardrum can rupture due to a scuba diver not equalising the ears on the descent. The difference in pressure across the eardrum on descent forces it to bulge inwards until eventually it will rupture. This lets water into the middle ear.

Symptoms of a ruptured eardrum while scuba diving are:

•A reduction in hearing;
•A ringing sound in the ear;
•After the ascent, there may be a bloody discharge from the ear.
Inner Ear Barotrauma While Scuba Diving

An inner ear barotrauma occurs when a scuba diver over equalises their ears on descent. Excessive Valsalva technique puts excessive force on the tiny membrane between the middle ear and the inner ear. These are called the round and oval windows.

Symptoms are vertigo, nausea, loss of hearing or a ringing sound in the ear.

This is the most serious ear injury to occur during scuba diving and can lead to permanent hearing loss in the ear. Medical attention should be obtained as soon as possible if a scuba diver suspects they may have suffered an inner ear barotrauma.

Swimmer’s Ear and Scuba Diving

Swimmer’s ear, or Otitis Externa, is an infection of the outer ear and ear canal. It is usually associated with the ears being wet and bacteria growing in the dark, damp ear canal.

For more information on Swimmer’s ear, refer to Suite101 Article: Causes and Prevention of Swimmer’s Ear.

Preventing Ear Injuries While Scuba Diving

A scuba diver should be aware of the high risk of injury to the ears from scuba diving. The main ways in which a scuba diver can prevent ear injuries while scuba diving are:

•don’t do a forceful Valsalva technique to clear the ears;
•if having trouble equalising on the descent, rise a few metres;
•avoid diving with a cold or any illness that results in the ear being congested;
If a scuba diver can’t equalise their ears, then they shouldn't scuba dive.

Damage to the ears from scuba diving can result in permanent hearing loss. Therefore it is wise for scuba divers to care for their ears and be well aware of the risks to the ears from the impact of pressure during scuba diving.

Using a Rigid Inflatable Boat for Scuba Diving

An inflatable boat for scuba diving conjures thoughts of a dinky toy that can’t take the punishment of a rough scuba dive trip. However, inflatable boats make an excellent scuba dive boat.

What is a Rigid Inflatable Boat?

These boats are not a true inflatable boat. Two large buoyancy collars are attached to a rigid aluminium hull. Hence the name: Rigid Inflatable Boat, or RIB.

The buoyancy collars are actually two tubes. The outer casing attaches to the aluminium hull by a track system with the inner tube, like a bicycle tube, fitting inside. The rigid hull forms a normal planing vee and the buoyancy collars attach on the side of this.

The inner tube should last about ten years, though the outer tube has to be replaced every three to five years depending on use.

This double tube arrangement has a few advantages. If a leak in the inner tube occurs it is a simple matter of removing the entire tube to repair it. A hole in the outer casing can be repaired from inside making the repair less noticeable. When the outer tube requires replacing it is almost like a new boat.

With the separate inner tube there is no chance of air escaping by wicking through the fabric.

The air pressure needs adjustment due to the seasonal changes in temperature.

How Good is a Rigid Inflatable Boat on the Water?

A RIB is a surprisingly solid boat. It has a feel that it can take any punishment that scuba divers can throw at it. The buoyancy collars are made of extremely tough vinyl that is forgiving but has the strength needed in such a boat.

Out in the open sea the characteristic of these boats becomes apparent. A RIB is an extremely dry boat. Many owners say their boat is “dry” but experienced divers would have spent long hours in scuba dive boats of similar size and have always copped spray on the trip to the scuba dive site.

But the RIB is different. It is possible to sit on the buoyancy collars and still not get spray in the face, though the safest place when under full power is on the deck.

The buoyancy collars not only give the boat its stability and flotation they also direct the spray away from the boat. This phenomenon is even more noticeable when punching into a messy sea of wind-blown chop on top of large swells. This can be useful if a scuba diver is prone to seasickness.

How Good is a Rigid Inflatable Boat for Scuba Diving?

At the scuba dive site the boat's stability comes to the fore. In swells and slight chop the buoyancy collars do their job again and smooth out the ride, even with divers moving around the boat. This makes gearing up a breeze, though organisation is needed as is usual on any scuba dive boat of this size.

Entering the water is the backward roll over the side: a simple manoeuvre on the buoyancy collars.

Getting back on board is another matter. The best way is to porpoise over the pontoons. It's simply a matter of removing the weightbelt followed by buoyancy compensator and tank, then kicking hard with fins and pulling up on the buoyancy collar’s safety ropes. The wetsuit slips over the wet vinyl of the buoyancy collars allowing the scuba diver to slide into the boat.

Using a Rigid Inflatable Boat for Scuba Diving

The Rigid Inflatable Boat is perfect as a scuba dive boat. It is stable, dry and has heaps of room. With some careful organisation, a 4.8 metre RIB with a 70 horsepower motor could take up to six divers.

This sized RIB would be suited for a quick trip out to the dive site, have the dive then back in. Two dives would be possible but the cramped conditions and wouldn't make for a comfortable time between dives.

A Rigid Inflatable Boat would have many uses in the dive industry. For research divers, dive club boats, dive trip operators who want a boat to take four to six divers out for a quick one tank dive. In fact they are suitable for any dive operation where a robust, stable dive platform is required.

The Most Beautiful Dive Sites in Costa Rica

Brilliantly colored corals, lazy sharks and giant turtles are just a few of the wonders to be experienced in the waters off of Costa Rica. However, this small country has a lot of coastline so it helps to know where the best dive sites in Costa Rica are before hopping in the water. Flanked by the Caribbean to the East and the Pacific Ocean to the West there are plenty of options for a Scuba diver to explore. Consider these dive sites when planning a Costa Rica diving vacation.

Experience the Best Dive Sites of Caño Island

Perhaps one of the most talked about dive sites in Costa Rica is Caño Island just 12 miles west of Drake Bay on the country’s Southwest coast. In the heart of a biological reserve the main attraction around this island are the large pelagic species swimming about. These include white tip reef sharks, bull sharks, over five species of dolphin, various rays, and turtles according to the dive operators Costa Rica Adventure Divers. Corals are also common although less abundant than in the Caribbean.

The island is surrounded by six dive sites with interesting rock formations creating stone pinnacles rising from the sea bed. The average dive depth is about 15-20 meters. The best dives occur from February to June.

Take a Scuba Diving Vacation to Gunacaste

Guanacaste province on the Northwest coast of Costa Rica is a launching pad to a few of Costa Rica’s best diving sites – the Catalina Islands and the Bat Islands. The town of Tamarindo on the mainland is only about 25 minutes from the Catalina Islands, an archipelago of about 20 rocks. The islands are well known for its sharks, sea turtles, and large schools of manta rays. The currents here can sometimes be strong, so the dives are generally recommended for more advanced divers. According to the tour operators Tierra Verde the best time to see schools of mantas are from December through May.

Meanwhile, the best time to dive the Bat Islands or Islas Murcielagos, is from March through November. Look for large bull sharks and eagle rays as well as plenty of corals. Caverns and bridges dot these dive sites which are slightly north of the Catalina Islands.

The Best Costa Rica Dive Sites in the Caribbean

Most Scuba divers spend the bulk of their Costa Rica dive time in the Pacific, however the reefs of the Caribbean should not be ignored. On the Southeast coast lies Cahuita National Park, just south of Cahuita town and about 43 kilometers south of Limón according to the Costa Rica Tourism and Travel Bureau website. The dive sites within the park are rich in coral gardens surrounded by multitudes of tropical reef fish. Look for brain corals, sea fans, angelfish, barracudas, and stingrays. Also look for the cannons on the sunken 18th century slave ship north of the river Perezoso.

Scuba Diving on a Christmas Caribbean Vacation

This Christmas, trade in cold sludgy sidewalks for white sand beaches with a visit to the Caribbean. The weather is beautiful with temperatures ranging between 75°F to 85°F and with the hurricane season over diving is looking good again. A Christmas Caribbean vacation is not complete with out learning about the area’s fascinating marine life. So grab a wetsuit and check out the Caribbean’s best dive sites.

Listen to Whales on a Scuba Vacation in the Turks & Caicos

The Turks & Caicos Islands are a great place to be for a Christmas Caribbean vacation as rainy season is over and whale season is just beginning. According to the Caribbean dive operators Bay Adventures website, humpback whales can be heard throughout the islands from December through April. The Columbus Passage separating South Caicos from Grand Turk is a major highway for migrating manta rays in the summer, humpback whales in the winter, and turtles year-round. Dive sites around the island are also home to coral gardens, colorful sponges, and schooling fish.

Take a Scuba Vacation to Cozumel, Mexico

December is a busy time for Cozumel and it’s no wonder so many people want to take their Caribbean Christmas vacation to Mexico. Cozumel Reefs National Marine Park is a place of great biodiversity and the government has gone to great lengths to protect it. Divers are required to pay a $2 entry fee per day and all funds go to reef conservation according to the tour operators Aqua Safari. The dive guides at Carayitos Advanced Divers do an excellent job of describing the various dive sites around Cozumel. Expect to see rays, sea turtles, nurse sharks, and large sea fans. Many of the dives around Cozumel are drift dives due to strong currents.

Find the Best Belize Diving on a Christmas Caribbean Vacation

Sunny skies are key to a successful dive vacation and December falls right inside of Belize’s dry season. Expect great visibility and calm seas while diving out of San Pedro on Ambergris Caye. According to the dive operators at Scuba-Belize.com there are over 40 named dive sites dotting the 20 miles of barrier reef running parallel to Ambergris.

Part of the second largest reef system in the world, the turquoise blue waters of Belize dive sites boast nurse sharks, stingrays, and schools of barracuda. Colorful corals are home to large schools of fish and lobsters. Belize is a popular destination for a Christmas Caribbean vacation, just watch out as there will be plenty of other tourists heading there too.

Avoid Caribbean Christmas Crowds on Saba

This undiscovered treasure is known as the “Unspoiled Queen” according to the tour operators, Cardonna Dive Adventures. Receiving only 25,000 visitors a year, this small island’s untouched dive sites make an excellent escape from Christmas crowds. Saba is the smallest island of the Antilles and offers scuba diving year round with water temperatures dropping to about 77°F to 80°F in the winter. Marine life includes tropical fish, groupers, reef sharks, and bull sharks. The dive sites are also well known for underwater mountains and pinnacles rising majestically from the seafloor towards the surface.

Scuba Diving at Mudjimba Island Scuba Dive Site

Mudjimba Island is a tiny island on Queensland's Sunshine Coast; a little over an hour’s drive north of Brisbane.

History of Mudjimba Island Scuba Dive Site

There are two Aboriginal dreamtime stories about Mudjimba Island.

The name Mudjimba refers to an Aboriginal legend in which a woman became stranded on the island, where she lived into old age.

The other story is about the creation of Mudjimba Island. There were two men: Coolum and Ninderry, who fought over a woman called Maroochy. Ninderry knocked Coolum’s head off and it landed in the sea to become Mudjimba Island.

Modern history tells of Mudjimba Island once being owned by actor Sean Connery. He was married to Australian actress Diane Cilento in the 1960s and early 1970s. They were said to have spent time on Mudjimba Island during their marriage.

Location of Mudjimba Island Scuba Dive Site

Mudjimba Island is about one kilometre offshore from Mudjimba Beach on Queensland’s Sunshine Coast. It is about three kilometres north of the outlet of the Maroochy River. This results in mediocre visibility. Fifteen metres on a good day, but average around seven metres.

The GPS coordinates for Mudjimba Island scuba dive site are:

-26.614611, 153.114674

What’s at Mudjimba Island Scuba Dive Site

The soft corals at Mudjimba scuba dive site provide an amazing array of colour. In a short scuba dive a diver may see many different colours of bright fluorescent soft corals.

This feature alone would make Mudjimba Island scuba dive site a perfect spot for macro underwater photography buffs.

Fish Life at Mudjimba Island Scuba Dive Site

A sad feature that can be found at many similar sites around Australia is the lack of large fish. Most have been taken on the fishing line over many years of fishing at the spot.

The occasional meal-sized bream warily swims through at Mudjimba Island, but the majority of the fish left are small tropical fish.

Scuba Dive Plan for Mudjimba Island Scuba Dive Site

Being an island, Mudjimba Island has to be a scuba boat dive. The island offers a safe comfortable dive in any prevailing winds, though anything over 15 knots can make the trip across from the Mooloolaba River boat harbour a bit uncomfortable.

Good scuba dive sites can be found all around the island, all in a maximum of 12 metres, which makes for long easy dives.

The corals are predominantly soft with many outcrops, bommies and gullies making an interesting seascape.

Snorkelling at Mudjimba Island Scuba Dive Site

Mudjimba Island is a good location for snorkelling. The coral gardens with a range of soft corals and rocky ledges start around two metres.

Mudjimba Island scuba dive site is a reasonable dive site. The poor visibility and lack of large fish life are a negative. A positive for this scuba dive site is the range of soft corals.

Mudjimba Island is a good second scuba dive site, after visiting other sites in the Sunshine Coast area.

Snorkeling the Cenotes in the Mayan Riviera

The Mayan Riviera has very few above ground sources of water and these cenotes join up to underground rivers that lead into the ocean.

Getting to Cancun

Upon entering the Cancun airport things are relatively easy to navigate. Customs lines are long but go quickly. Luggage is then picked up and everyone heads to immigration, which can take a bit of time as each piece of luggage is scanned upon exiting. After that there are lots of taxi people that are hanging around, so it’s a good idea for travelers to have made reservations and know where they are going before exiting.

Renting a Car in Cancun

Don’t be afraid to rent a car here. It’s easy to get around and hard to get lost as there is only one main road. Beware of insurance additions at the rental car agencies. Rental costs can easily be doubled with the addition of taxes and the insurances that are required. Also be aware of girls in the rental car area trying to sell timeshares.

Where to stay in Cancun or Playa Del Carmen?

Either is fine. Playa del Carmen is actually closer to the Cenotes. A recommendation is the Barcelo Maya Palace All Inclusive resort. It's massive, has great food and great accommodations.

Hidden Worlds

The best cenote snorkeling is at Hidden Worlds. In addition to snorkeling, they also offer zip lining and rappelling. Different package options are offered. For cenote snorkeling, The Church Cenote and Tak be Hal Cenote are both very large caverns. A guide is provided and will point out items of interest. To get back to the cenotes, travel is by “Mexican Limo” which is a 15 minute tractor/bus through the jungle. The first cenote, the Church, has some pretty steep stairs that visitors actually have to climb down backwards. The water in the cenote is very cold, 72 degrees, so be sure to rent a wet suit. There aren’t many fish in the cenotes but there are lots of stalactites and stalagmites.

Paths through the jungle will lead to the next cenote, Tak Be Hal, but don’t worry there is still a guide to get everyone there. Bring bug spray as there are tons of mosquitoes. Make sure to reapply it when getting out of the water. This cenote is even a larger cavern than The Church and patrons can actually repel or zip line into it.

Snorkeling in fresh water is definitely a different experience than snorkeling in salt water and is highly recommended.

Scuba Diving Trips to Gran Canaria

Scuba diving trips to the island of Gran Canaria are becoming increasingly popular. The island is something of an unappreciated gem for divers and is rapidly gaining recognition as one of Europe’s great scuba diving locations.

Why Gran Canaria is a Great Scuba Diving Location

The island rests amid a confluence of different seas and oceans, making it something of a unique scuba diving environment. Marine species from the Mediterranean, Atlantic, Red Sea and Africa can be found in Canarian waters. The island is host to some of the most beautiful marine life on earth.

Manta Rays are regularly seen from October onwards, especially in the North of the island, around the Caleta region. Divers have reported seeing schools of the huge animals during the winter months. Other species include sizeable barracuda, angel sharks, trumpet fish, monumental schools of Roncadores, cuttle fish, moray eels, snapper, octopus and a variety of stingrays.

The El Cabron Marine Reserve in Arinaga

In 2004 UNESCO approved Gran Canaria as a World Biosphere Reserve and nowhere represents the beauty and diversity of the island’s marine environment better than EL Cabron.

One of only three marine reserves in the Canary Islands, El Cabron is a Mecca for divers of all abilities. This protected reserve (into which boats cannot travel) is home to a wide array of sites, allowing divers to explore a plethora of submerged volcanic mounts, walls, canyons and swim throughs.

Stingrays, angel sharks and immense schools of barracuda patrol this underwater paradise; while moray eels, octopus and even sea horses make their homes in the rocks, nook and crevices of the volcanic strata. Visibility in the reserve is generally excellent, rarely falling below 20 metres. No scuba diving holiday to the island would be complete without a trip to Arinaga.

Wreck Diving

While most of the popular diving is to be found along the southern reaches of the island (incidentally where the major holiday resorts are to be found) there are some excellent wrecks worth exploring in the northern part of the island, off the coast of the capital Las Palmas.

Two of the largest wrecks in the Canaries (the Arona and the Kalais) are to be found a short boat ride out of the port of Las Palmas. These dives, ranging as they do from between 27-35 metres are for the more experienced only, as conditions can be somewhat mercurial in the North, with strong currents commonplace.

The Mogan wrecks, just outside the popular tourist village in the South, are an extremely popular diving destination for the slightly less experienced or adventurous diver. They are two small wrecks sunk to provide an attraction for the daily Yellow Submarine trip. Most dive schools time their entries to match the hourly voyage of the submarine and the trip is a bizarre and unique addition to any diving holiday on the island.

Gran Canaria is a Year Round Scuba Diving Location

The island has one of the world’s best climates, with temperatures still approaching the thirties throughout the winter months. In terms of water temperature it is not uncommon to see surface temperatures of 21 or 22 degrees Celsius in December. The water rarely drops below 18 degrees, even in the coldest of the winter months. The average temperature hovers around 23 degrees Celsius.

In addition to being a year round diving destination, holidaymakers are able to dive on every side of the island, rather than simply the over-fished and busy tourist areas, which is the norm throughout the Mediterranean.

An Island of Contrasts

The island itself is easily accessible from all parts of the European mainland and North America, which adds to its attractiveness as a holiday destination. Holiday accommodation exists to suit every taste and budget. The island offers travellers a welter of contrasts, from the bustle and excitement of the thriving southern resorts to the peace and solitude of the mountainous centre of the island.

Non-divers or those taking a rest from the undersea world will find much to do throughout the year. The island is ferociously Spanish in terms of its cultural outlook and festivals and celebrations take place almost every month, adding spice to any diving holiday. In terms of gastronomy the island is a gourmand’s delight, with every conceivable culinary taste catered for. Visitors will most certainly eat well while on their diving holiday.

Visit Gran Canaria for a Great Scuba Diving Holiday

The island offers something for every diver, from protected bays to challenging deep wreck dives. Excellent underwater visibility and warm temperatures ensure relaxing and stress free diving. The island’s is home to numerous PADI Five-Star diving schools and equipment and expert tuition and guidance is readily available. For too long the island has been ignored as a world-class diving destination, all that looks set to change.

Diving Busselton Jetty, South West Australia

Busselton Jetty is the longest wooden jetty in the southern hemisphere and was built over a 95-year period from 1865. The main sources of income for the area in its 19th century heyday were timber and whaling. For this purpose jetties were built at the quaintly named towns of Wonnerup, Busselton and Quindalup in Australia's south west. Only the Busselton Jetty remains.

The jetty stretches a remarkable two kilometers into Geographe Bay. Closed as a port in 1972, the 138-year-old jetty has since been ravaged by both fire and cyclone. Its repair, and its subsequent protection, are due to the efforts of the local community who are now pushing for the jetty to be given full protected area status because of its rich marine life.

Its rickety wooden planking and lethal nails has that real old world charm of the colonial antipodes and it it is added to by the bright red train that now takes tourists down to the end of the jetty. But its underwater view is the real spectacle.

Leeuwin Current Brings Rich Marine Life to Cooler Waters

Every year in autumn and winter, the Leeuwin Current brings with it a narrow band of warm water down the West Australian coastline. It's this warm southerly current that’s responsible for bringing the incredible and diverse variety of tropical and sub-tropical species into Geographe Bay. Coral grows here at a latitude of 33 degrees south making it the most southerly coral growth in the world.

There have been around 300 hundred marine species recorded here. Huge schools of yellow tail scads cascade around the wooden pilings. Tropical and subtropical species litter the timber forest of the jetty’s legs. Soft coral and gorgonians deeply encrust every piece of timber, while ascidians hang in clusters off the pilings and sponges carpet any spare surface available. It is the best of any living reef. Groups of old wives fish sit completely still, suspended between timber legs while perch and gurnards happily navigate around the reef. A diver would commonly encounter around a dozen types of nudibranchs.

Busselton Jetty Underwater Observatory

Swimming in past the pilings towards shore, you reach the only underwater observatory in the southern hemisphere. Opened in 2003, you can be watched and snapped by tourists as they see you as part of the underwater seascape. It’s perfect for the non-divers in your party. They too can appreciate the extraordinary spectacle that is Busselton Jetty’s marine life. The jetty is already part of the Geographe Bay Marine Reserve Area and there are calls to make the area a complete no fishing zone, so protecting its remarkable variety of life.

Scuba Diving With the Numbfish

The shock from a Numbfish is not dangerous, but it makes this fish worth being aware of for a scuba diver.

The Numbfish is also known as the Numb Ray or the Electric Ray.

The Electric Shock of the Numbfish

The Numbfish has a unique organ on the top of the head containing a bank of 200 to 500 hexagonal cells. This organ establishes a voltage difference between the top and the bottom of the Numbfish, the top being positive and the bottom negative.

When a scuba diver, or another fish, touches this Numbfish, the voltage discharges through the scuba diver giving an electric shock.

The Numbfish can deliver a jolt of around 200 volts which can be enough to cause cramping in a scuba diver’s muscle in the arm of leg.

Within about 10 minutes, the Numbfish can deliver up to 50 successive voltage discharges. However, the voltage in the successive discharges falls to around 80 volts.

Why Does the Numbfish Have the Electric Shock Capability

It is believed that the Numbfish has the electric shock capability for two reasons:

1.As a defence mechanism. If a larger fish wants to take a bite, the Numbfish hits it with a sudden voltage.
2.As a way to catch its prey. Lying in the sand it waits for small fish, crabs, or worms to crawl across it. It then wraps its body around the prey and stuns them with an electric shock.
Details of the Numbfish

The Numbfish is a flat fish with the eyes on the top of its body. It has an oval body that elongates to the end with a smaller oval at the back with three small fins.

An adult Numbfish grows to around 700 millimetres (27 inches), with the width across its head being about the same as it is long. It is a fairly dull colour; dark brown on the top, and a yellow-white underneath.

It moves through the water in the normal manner of a ray by pulsating the outer edges of its body in a waving motion. It is a weak swimmer so doesn’t swim much, preferring to lie on the sea floor, partly buried on the sand waiting for its prey.

The Numbfish is viviparous, which means it gives birth to live young rather than laying eggs.

Apparently the Numbfish can swallow exceptionally large fish for its size. According to Ern Grant in Guide To Fishes a 600 millimetre Numbfish was once found with the tail of a 2.3 kilogram flathead poking out its mouth!

Where is the Numbfish Located

The Numbfish is a reasonably rare fish. That is, a scuba diver won’t see one on every dive. On coral reefs it is usually found half buried in the sand around the edges of coral bommies and rocky outcrops.

In Australia, the Numbfish is found along coastal waters in Queensland, including the Great Barrier Reef, and down the New South Wales coast. It has also been seen in the Great Australian Bight and along the West Australian Coast.

Scuba Diving Risks and the Numbfish

There is a slight risk for scuba divers in encountering a Numbfish. The most common way for this interaction to occur is if a scuba diver accidentally kneels on one that is hiding in the sand.

To avoid getting an electronic shock from a Numbray, scuba divers should pay close attention when settling onto a sandy sea-floor during a scuba dive. Good scuba buoyancy control can assist in achieving this.

The electric shock from a Numbfish is not strong enough to kill, but can be a catalyst for the start of other problems especially if the scuba diver gets a sudden fright and is already anxious underwater.

A scuba diver shouldn’t be concerned about sharing the waters with a Numbfish. These unique fish are simply one of the many animals that make scuba diving so fascinating.

Facts on Scuba Diving With the Manta Ray

Scuba diving with a Manta Ray is a great experience when underwater. These majestic creatures slowly gliding through the water are both awe inspiring and humbling.

Bruce IliffPosted on Mar 13, 2010
Scuba Diving With Manta Ray is a Unique Experience - R. CampbellA scuba diver experiencing a Manta Ray will almost always result in the lucky diver poking their head above the water at the end of the dive ecstatic at having the chance to swim with these majestic marvels.

Features of the Manta Ray

The Manta Ray is the largest of the ray family (Myliobatidae). It has huge wings that it uses to swim. And like all rays, such as the Numb Ray, it appears to ‘fly’ through the water like a bird.

The Manta Ray has large flippers that protrude from the front of the body, just in front of its mouth. These feeding flippers appear like horns, giving the Manta Ray its other name of Devil Ray.

The front flippers are used to scoop plankton on the surface of the water into its mouth.

Manta Rays average around 4.3 metres (14 feet) across the wings, but have been known to grow up to 6.7 metres. They can weigh up to 1,400 kilogram, but the average weight is about 750 kilograms (1,650 pounds).

They are a dark blue-black colour on top, with a pure white underside. This colouring is obviously a defence mechanism as the white underbelly will appear to blend in with the light of the surface of the water when viewed from below. This is especially important as the Manta Ray is a surface feeder, with the main predator being the larger of the reef sharks, such as the tiger shark.

Manta Rays are found in warm tropical waters around the world, which places them in the region between 35 degrees north and 35 degrees south latitude. Being surface feeders, they are common on reefs such as Australia’s Great Barrier Reef.

Observing Manta Rays on the Surface

One of the unique features of the Manta Ray is that they will occasionally launch themselves from the water and crash back on the surface with a huge slap and a shower of spray. This action is thought to be either socialising or a way to avoid predators. Another theory is that this has something to do with removing parasites from its skin.

When Manta Rays are feeding on the surface, occasionally the wing tips break the surface and appear like two shark fins.

Scuba Diving With Manta Rays

It appears that Manta Rays are quite curious creatures. They are known to approach scuba divers, either enjoying the interaction or simply wanting to see what is happening.

Manta Rays don’t appear too concerned with underwater flash photography, or with the sound of the scuba gear bubbling away. In fact, some divers theorise that Manta Rays like the feel of the bubbles on their underbelly and seek out scuba divers for the experience.

The best advice for scuba divers wanting to get up close to Manta Rays is to:

•Find a common cleaning station where the Manta Rays come to get the parasites cleaned from their skin. The local divemaster may know the best spot.
•Don’t make sudden movements. Generally a scuba diver should stay in the one spot and simply observe. The Manta Ray will come as close as they want.
•Don’t attempt to touch the ray, as the protective mucous on the skin could be rubbed off by a dive glove, leaving the animal possibly susceptible to infection.
•Manta Rays should never be ridden.
The less action a scuba diver takes to scare a Manta Ray, the more likely it will be that the ray stays around and provides the scuba diver a great experience.

Two Different Types of Scuba Dive Warning Flags

Scuba divers travelling to exotic dive sites around the world are confronted with two different types of scuba dive flags. They both convey the same warning message.

Bruce IliffPosted on Mar 21, 2010
Blue and White Scuba Flag in Use - Bruce ILIFFThere are two different types of scuba diving warning flags used around the world.

1.A blue and white dive flag with the blue section as a swallow tail,
2.A red dive flag with a white stripe from top left to bottom right.
Many divers would be aware of both these types of flags, especially if having travelled on scuba diving trips around the world.

Both these scuba dive flags convey the same meaning when flown from a scuba dive boat. It is the independent development of the flags has resulted in having the two different styles.

History of the Red and White Scuba Dive Flag

It is generally accepted that the development of the red and white scuba dive flag is accredited to an American pioneer scuba diver by the name of Denzel James Dockery. In the 1950s, Dockery was one of the early pioneers and decided he needed a flag to warn boats in the general vicinity when he was underwater.

The Navy’s flag for warning is a solid red colour and is referred to as the “Bravo Flag”. Dockery started with this and simply put the diagonal stripe across it.

Dockery then started trying to get his flag accepted as the main scuba diving warning flag. Gradually it was picked up by the fledgling scuba diving community and has now become entrenched as the main scuba diving warning flag in the USA and Canada.

History of the Blue and White Scuba Dive Flag

The blue and white scuba diving flag developed from the international maritime signal flags. These are a system of flags that have been recognised internationally for over 200 years.

The blue and white flag signified the letter “A” when flown as part of the alphabet. Therefore it was called the Alpha flag.

A single letter flag also conveys a different message when flown by itself. Initially, the message the Alpha flag conveyed was “The boat is undergoing a speed trial.” However it has been changed to convey the message: “A scuba diver is down. Keep clear at low speed.”

Both Scuba Dive Flags Convey the Same Message

Though both scuba dive flags look completely different they convey the same message.

The only difference is in what part of the world a scuba diver comes across each flag.

The local scuba dive shops will be able to provide details of what flag is recognised in the area.

Using a Scuba Diving Flag

A scuba diving flag should always be flown from a scuba dive boat when a diver is below.

When shore diving, a scuba diving flag should be placed on the water in a fixed location just out from the shore. The flag can be set up on a float with a rope tying it off on the sea floor.

For drift dives, a scuba dive flag should be towed along behind the divers. This can be done by setting up the dive flag on a float, such as a car tyre tube.

Whichever scuba diving warning flag is used, they should always be flown as a safety precaution when diving.

Must a Scuba Diver Carry a Snorkel When Diving?

There are equally good arguments for taking a snorkel on a dive or not. In most situations it is personal preference and the type of scuba diving being undertaken.

Bruce IliffPosted on Mar 27, 2010
Scuba Diver With Snorkel - Bruce ILIFFA number of scuba divers do not carry a snorkel while diving. There are two schools of thought in this long running debate on whether or not a scuba diver should. The debate squares off with safety on one side against comfort and ease of diving on the other.

There is also the compromise position of carrying a snorkel while scuba diving, but not having it attached to the mask.

Yes – A Scuba Diver Should Carry a Snorkel When Diving

The main reason for carrying a snorkel when scuba diving is the simple consideration of diver safety.

With the snorkel firmly attached to the mask, the diver will know exactly where it is when needed on the surface. And it can be easily deployed; there is no scrabbling around trying to find it. This can be especially important in a choppy sea and needing to spend some time on the surface at the end of the dive.

No – A Scuba Diver Does Not Need to Carry a Snorkel When Diving

The main argument for not having a snorkel attached to the mask is that the snorkel doesn’t assist the scuba diver while underwater; so why have it attached to the mask?

Also, when underwater the snorkel gets in the way.

When swimming hard underwater, or in a strong current, the snorkel flapping around can pull on the mask and may even break the mask’s seal on the face.

Another argument is that if the snorkel is on the mask it can get caught on things: snagged in fishing line, kicked by other divers, or getting stuck when poking the head into a crevice to check out what is inside.

There is also a school of thought that a diver should always have enough air in the tank when returning to the surface to exit from the water.

If a Scuba Diver Does Take a Snorkel, Where Should it be Carried?

Collapsible snorkels are available. These can fit in a BC jacket and be out of the way.

Some scuba divers store their snorkel in their buoyancy jacket. They use it on the surface when first entering the water, then stuff it down the buoyancy compensator jacket on the descent. It is then easily located on the ascent.

Another common place to store the snorkel is on the leg, held on with the straps of the knife holder. This is a reasonable option as it is out of the way during the dive and easily accessible.

Do Not Tuck the Snorkel in the Weightbelt

Tucking the snorkel into the weightbelt is another common solution. However, this should be avoided. If an emergency arises during the dive, depending on the situation, one of the first actions can be to drop the weight belt. In the heat of the moment, the snorkel can be forgotten and it can fall to the seafloor while the scuba diver heads to the surface.

Without a weightbelt, the scuba diver will end up on the surface and that is the place a snorkel is needed most.

There is no real hard and fast rule on which option to use as there are good arguments on both sides. Safety is obviously a serious consideration. Having a snorkel easily deployed on the surface has to be the safest; though an argument can be made that in some situations it is safer not to have a snorkel attached to the mask.

Therefore, as in most scuba diving considerations, it comes down to personal preference and the type of scuba dive being undertaken. A drift dive with the possibility of a long swim back to the exit point might require a snorkel. While on an easy shore dive with the same entry and exit point, the snorkel may not be required.

Good Breathing Techniques for Scuba Diving

Every scuba diver should master good breathing techniques underwater. Increased safety, enjoyment, and longer time underwater can come from improving breathing technique.

Bruce IliffPosted on Mar 27, 2010
Scuba Divers Should Improve Breathing - Bruce ILIFFGood breathing is an important consideration in scuba diving. The body needs adequate levels of oxygen for cells to function. This is especially important when undergoing the rigours of scuba diving.

Good breathing is also needed to remove nitrogen from the body. Though not as significant if a scuba diver is not entering into decompression times, removing excess nitrogen from the body is just as important as the need to get oxygen into the body.

Breathing for Scuba Buoyancy Control

Good breathing techniques can assist with buoyancy control underwater. A scuba diver will rise when taking a breath as the lungs expand with air and the body’s buoyancy increases. And when air is expelled from the lungs, a diver’s buoyancy decreases and the diver will sink.

This use of breathing techniques is something that all scuba divers should be aware of and practise regularly. For more information, on using the breath for buoyancy control refer to Suite 101 article: Scuba Diving Buoyancy Control.

Breathing to Address Stress and Anxiety Underwater on Scuba

Scuba diving is a stressful activity mainly due to the unnatural environment a diver’s body is in. The human body was not built to swim underwater like a fish, but fortunately innovation has allowed this to happen.

Good breathing control is one of the best ways to combat any symptoms of stress or anxiety while underwater, as the good flow of oxygen to the brain helps reduce rising anxiety.

One of the most common physiological signs of stress is a person starts to “chest breath”. That is, they take short, shallow breaths from the top of the chest, rather than the normal rhythmic long, deep breaths from the lower abdomen. This starts a cycle going whereby the oxygen to the brain is reduced, so the body starts to seek more oxygen and the breaths get shallower and quicker. This can lead to hyperventilation and sometimes, in extreme cases, fainting.

When underwater on scuba this can be a significant problem, so the need for good breathing techniques is vital for a safe and comfortable dive.

For more information on stress and anxiety while scuba diving refer to Suite 101 article: Scuba Diving Anxiety and Panic.

Breathing to Increase Time Underwater on Scuba

Good breathing techniques can lead to a decrease in air consumption. Some divers roar through their air, while others consume much less. This doesn’t always mean that one diver is more relaxed as it can also indicate that one diver may need more air than another.

However, in the majority of situations, good breathing techniques will help to reduce air consumption on scuba and consequently more time underwater.

Good Underwater Breathing Techniques

The main objective for good underwater breathing technique is to take slow, deep breaths.

When first starting on the practice of improving breathing techniques, the breaths should be deliberate. That is, a diver should concentrate on slow, deep breaths. And then gradually this will become a natural way of breathing.

Physically trying to relax underwater will also assist in breathing as the body won’t be craving the next breath. This can be quite easy on those relaxing dives, like a shallow drift dive on a coral reef. But for increased anxiety dives, such as decompression dives, or wreck penetration dives having a good breathing technique can be a bit more difficult.

As with every sport, practice is the key. A scuba diver should be concentrating on improving breathing techniques on those easy dives so when faced with the dives that result in a higher breathing rate, the rate doesn’t go to that frenetic pace that can lead to further problems.

Dive Around Texas Event

Texas offers more than 30 places to scuba dive, from rivers to the Gulf of Mexico. Dive Around Texas offers prizes for diving 12 times in four different sites.
Melissa GaskillPosted on Apr 6, 2010
Diving a Rig at the Flower Gardens NMS - M. GaskillAn annual event to promote and celebrate diving in the Lone Star State, Dive Around Texas challenges divers to make a minimum of 12 dives in four different locations in Texas. Divers can sign up at participating dive shops; the $25 registration fee includes a t-shirt.
Dive Around Texas Rules
Divers simply log each dive, then have a participating dive shop verify the dive with a special "Dive Around Texas" stamp. Those who complete the 12-dive, four-site challenge receive a ticket to the Awards Recognition Day, October 3, 2010 in San Marcos and become eligible for dive-related prizes, including dive trips. The more dives completed, the more chances to win. Divers must be present at the Awards Recognition Day to win, or have their verified log book submitted by a participating retailer.
Participating Dive Shops
Texas dive retailers participating in Dive Around Texas 2010 include:
1.Ascuba Venture, Corpus Christi
2.Blue Dolphin Dive Center, Temple
3.Dive West, Dallas
4.Dive World, Austin
5.Dive World, San Antonio
6.Gigglin' Marlin Divers, Houston
7.Oak Hill Scuba, Austin
8.Scuba Center, Tyler
9.Sea Sports Scuba (3 locations), Houston
10.Tom's Dive and Swim, Austin.
11.The Dive Shop, San Marcos
Divers can check to see if other dive shops are participating, as this is only a partial list. If your local dive shop isn't participating, ask them to join up.
Dive Sites in Texas
Texas dive sites include rigs and coral reefs in the Gulf of Mexico, dozens of lakes, a number of rivers, quarries, and even an old missile silo. one of the most popular spots in the Gulf is the Flower Gardens Banks National Marine Sanctuary, where coral reefs grow on the top of salt domes protruding from the sea floor, 60 to 100 feet deep. The Flower Gardens are an overnight trip on a live-aboard and an advanced dive site thanks to currents, depth, and a location 100 miles from shore. Local dive shops can arrange a trip on the R/V Fling, which departs from Freeport. Other popular Gulf of Mexico dive sites lie off South Padre Island and include the Texas Clipper and other sunken ship reefs, and offshore rigs. These can be half-day or all-day dive trips.
Lakes known for diving include Lake Amistad National Recreation Area (where divers also can rent houseboats), Canyon Lake, Lake Travis, Lake Belton, Toledo Bend, and Lake Meredith National Recreation Area. Most offer shore as well as boat diving. State parks that offer diving include Lake Ray Roberts, Lake Whitney, Possum Kingdom and Tyler State Parks. Balmorhea State Park in West Texas has a spring-fed, 25-foot deep pool with excellent visibility.
Divers also enjoy the clear Comal River in New Braunfels and the San Marcos River. Aquarena Springs in San Marcos, which is affiliated with Texas State University, has a science diving program and qualified divers can volunteer for a variety of monitoring and research projects.
Private dive sites in Texas include Blue Lagoon, a former quarry near Huntsville, Athens Scuba Park, Mammoth Lake near Houston, and Dive Valhalla, a 180-foot deep, water-filled missile silo near Abilene.
Dive operators and dive shops offer a variety of special events and dive opportunities as part of the event. The Dive Around Texas challenge offers a good inspiration to get out and try some of the excellent and fun diving available in the state.

Symptoms of Anxiety in a Scuba Diver on the Surface or Underwater

For some divers, scuba diving is stressful activity. It is useful for a scuba diver to recognize signs of anxiety and stress in themselves and others.
Bruce IliffPosted on Apr 16, 2010
Relaxed Scuba Divers Before the Dive - Bruce ILIFFSwimming underwater using mechanical devices to breathe off a tank of compressed air is unnatural. And being in an unnatural environment can lead to stress and anxiety in some divers.
Why Scuba Diving Can be Stressful
Though scuba gear has evolved to such an extent that scuba diving is now quite safe, there are many things that can go wrong. Equipment problems, interaction with the marine life with sharks, stingers and other nasties lurking in the deep. Even a scuba diver’s fitness levels and physiology can be a source of anxiety.
Anxiety can be a circular problem, with the symptoms of anxiety (such as a racing heartbeat) leading to increasing stress levels.
Being aware of symptoms of anxiety is the first step in rectifying the problem.
Recognising symptoms of anxiety before and during a scuba dive, both for the diver and the diver’s buddy, is useful as problems can be addressed before they become more serious.
Symptoms of Anxiety Before the Scuba Dive
There are symptoms that a scuba diver may exhibit before getting in the water. These may be displayed by either a diver themselves, or may be seen in another diver.
•Feelings of agitation. A diver may exhibit a restlessness that is out of character.
•Checking and re-checking scuba gear.
•Signs of physical discomfort in the digestive systems: stomach pains or cramps, excessive trips to the toilet, burping or flatulence.
•Feelings of nausea that may be stated as seasickness.
•Stating reasons for not wanting to go on the dive. These may be statements like “it is too rough”. Or “the current might be too strong.”
•Signs of changes of physiology; like unnatural sweating or shallow breathing.
•An abrupt attitude with signs of aggression.
•Being over-critical of things or other people.
Symptoms of Anxiety During the Scuba Dive
After an anxious scuba diver has ducked under the surface of the water, symptoms of anxiety can manifest in other ways.
•Excessive arm and leg movements. This may be accompanied by a feeling that the normal slow finning is not effective. The arms may start clawing at the water to assist in swimming.
•Fussing around with equipment: checking buckles, adjusting the weightbelt, fiddling with the dive gloves.
•Excessive checking of air supply and dive computer and/or watch.
•Feelings of nausea; maybe even vomiting
•Feeling of claustrophobia; sometimes accompanied by a desire to make a rapid ascent.
•Equipment, such as the wetsuit or buoyancy compensator, feels too tight and restrictive.
•Unable to control buoyancy.
•Increase in breathing rate; taking short, deep breaths that use air rapidly.
•Eyes may be wide open or “bulging”. They may be in a fixed stare, or flicking around but not focused on anything.
•The diver may be darting around under the water going from one thing to another with no particular focus on the dive. That is, they simply don’t appear to be relaxed.
Dealing with an Anxious Scuba Diver
A scuba diver exhibiting signs of anxiety should be a cause for concern. Both for the diver suffering from this malady, and for the other diver in a buddy pair or part of the dive group.
Every diver should be constantly on the lookout for signs of anxiety within themselves, and in any other divers that they may be associated with.
For advice on how to address anxiety while scuba diving, refer to Suite 101 article: Scuba Diving Anxiety and Panic.
An anxious diver is not only a safety concern, but also the diver won’t enjoy the dive due to the anxiety overwhelming him or her. This could mean the diver may not continue with their diving career and they might miss out on the great experiences that come in the underwater world.

How Does the Hard Hat Diving Helmet on an Old Diving Suit Work?

Many modern era scuba divers show interest in the pioneer divers and their suits and hard hats. Understanding how these helmets work is useful knowledge.
Bruce IliffPosted on Apr 16, 2010
Old Style Diving Suit and Helmet - Public DomanThe hard hat diving helmet of the old style diving suits worn by the original deep sea divers were the first scuba regulators that allowed a human to breath underwater.
They were crude in their design, worked well enough to be functional; but in the pioneering underwater world with increased pressures and treacherous conditions, the diving helmet was also a dangerous piece of equipment.
The old diving helmets were made of copper and attached to the diving suit via a heavy plate sitting on the chest.
Air was pumped into the suit and helmet via a pipe from the surface.
The air line from the surface limits the depth the suited diver can go. The suits had heavy lead shoes that worked against the suit’s buoyancy to keep the diver on the sea bed.
The helmet had three or four glass windows to allow the diver to see out. The technical term for these is “lights” and they may have a metal mesh or grate over the glass to prevent breakage.
How Does Air Enter an Old Style Diving Helmet?
The air line from the pump on the support boat comes down to the front of the diver and then under his arm to the back of the helmet. Having the line in front of the diver means he can hold onto it and know where it is at all times.
Passing under the diver’s arm also prevents the air line from getting snagged on things underwater. Or breaking off at the connection to the helmet if the line gets a sudden jerk due to waves acting on the support boat.
The air hose connects to a valve, downward facing, at the rear of the helmet. This valve is one-way so it allows air into the helmet and suit, but not out. This is set up so that if the air flow suddenly stops, the air trapped in the helmet and suit may be enough for the diver to ascend to the surface.
The air flows into the helmet via a series of ducts that sets up a swirling movement of air within the helmet. This keeps the stale air away from the diver’s face.
How Does Air Get Out of an Old Style Diving Helmet?
The air exits the diving helmet via an outlet valve. Depending on the type of suit and helmet, the outlet valve may be positioned on the helmet, usually on the right hand side. Some of the old diving suits have the outlet valve on the chest plate.
Air is pumped into the suit, the diver breathes as required, and air is exhausted out the outlet vale. This outlet valve is adjustable so the diver can regulate the air flow, and therefore the air quality, in the helmet.
The adjustment of the outlet valve is a balance between the amount the surface pump can deliver, the quality of air in the suit and the amount of air needed in the suit to control the diver’s buoyancy.
The Spitcock in Early Diving Equipment

Another unique feature of the old style diving helmets is the spitcock. This is a basic valve usually positioned to the right of the main “light”, and around the level of the diver’s chin.
The main purpose of this valve was to act as a quick dump valve. If the air was building up in the suit and the diver became too buoyant, the diver could open the spitcock and bleed off some excess air.
Another use of the spitcock is for the diver to clean the face plate of the window. Inside the helmet the air was hot and humid causing that common malady for all divers: fogging of the face mask.
The diver would open the spitcock a fraction and the outside water pressure would force a small stream of water into the diver’s mouth. The diver would then squirt the water onto the faceplate of the “light” washing away the fogging.
Knowing how an old style diving suit and helmet works is a useful topic of conversation for the modern scuba diver. Something to discuss on a scuba dive holiday, or when chatting about the underwater world in general.

Tying Knots That May be Used in Scuba Diving and Boating

Knowing how to knot a rope can be useful in scuba diving. The knowledge of a few basic knots can save frustrations in a number of scuba diving situations.
Bruce IliffPosted on May 1, 2010
Knots in Scuba Diving Used in Water and on Boat - Bruce ILIFFIn scuba diving there is a need to know some basic knots. These knots may be needed underwater, or more commonly when on the dive boat.
Tying the Reef Knot
The reef knot is used to join two lengths of rope. In a scuba diving situation, this may be when needing to join two pieces of rope to form a safety line to trail out the back of the dive boat.
Take the two ends of the rope, one in each hand. Put the right hand rope over the left and twist it under and up. Then the left side end (the original right hand one) is put back over the right hand rope. Twist under and pull the knot tight.
The lay of the ropes should be symmetrical. When the two ends of the rope are pushed towards each other the knot opens up, even after a day’s hard sailing.
The best way to remember this is: 'right over left and under, then left over right and under.' The 'right' or 'left' referring to the rope end on the right or left side.
The Bowline Knot in Scuba Diving
The bowline gives a loop at the end of a rope that won't slip and is easy to undo. This knot could be used when setting up a buddy line between two divers. This is a short length of rope that each diver holds, so they don’t get separated.
A buddy line is commonly used in night scuba diving to prevent a dive buddy pair separating. It can also be used for a scuba divemaster to keep close to a nervous scuba diver.
A loop in the end of the safety line trailing out the back of the dive boat could be useful for a diver to hold on if needed.
Tying the Bowline Knot
Near the end of the rope make a small loop. This is not the size of the eventual loop. The end of the rope that goes to the right should lie on top of the end to the left.
To make the final loop, take the right hand end and bring it back and come up through the first loop. This second loop will be the final loop. Take the end that has come up through the first loop and take it under the end that comes from the left. Then around and back through the original loop.
The Figure of Eight Knot in Scuba Diving
The figure of eight knot is used to put a knot in a rope to be used as a stopper, or as a marker on a rope. It is commonly used in sailing to prevent the end of a rope from sliding through a cleat.
The knot mostly used for this purpose is the ‘granny knot’ which is a simple loop in the rope. This works fine until trying to undo the knot! After getting wet and jammed it can be impossible to undo. Pliers are sometimes needed.
In scuba diving, the figure eight knot can be used on a shot line. This is a weighted rope that is put over the side of the boat that provides an indication of the depth. A weight, like a weight belt, is attached to the end of the line, and small knots are put in the rope at specific intervals to show the depth. As the scuba diver descends, they can get an accurate idea of their depth.
This may be used for calibrating or checking depth gauges. Or maybe to accurately signify the 10 foot and 20 foot depths for decompression stops.
Tying the Figure of Eight Knot
To do the figure of eight knot, form a loop in the rope with the end going under the rope. Take the free end and go over and around the rope then up through the loop from the bottom.
When pulled tight the lay of the rope looks like the figure eight. This knot will come undone with ease, even when wet.
The basic scuba diving knots described here are some of the basics that can assist in some areas of scuba diving. Knowledge of a few knots such as these can be useful for a scuba diver.

South Texas Dive Week

The fourth annual South Padre Island Dive Week, September 17-26, 2010 includes contests, prizes, and specials on scuba diving opportunities.
Melissa GaskillPosted on May 3, 2010
Rig Diving in the Gulf of Mexico - M. GaskillIn September, the water off the south coast of Texas is warm - 83 degrees - and clear - visibility an average 85 feet - and South Padre Island hosts a special diving event celebrating the sinking of the Texas Clipper in 2006. The ship rests on the floor of the Gulf of Mexico about an hour from shore, her top at approximately 65 feet and bottom at 130 feet or so. Coral, sponges, anemones and other sessile marine life have quickly turned the ship into a living reef, popular with snapper, jacks, queen angel fish, butterfly fish and a variety of other colorful tropical fish.
SPI Dive Week Events
During Dive Week, two-tank trips to the Texas Clipper are only $165, with a marine biologist on board during dives to help divers identify the tropical and pelagic fish and other marine life that has populated the sunken ship. Trips are aboard American Diving's MV Diver I, which has an air-conditioned passenger area, open front deck, and on-board toilet. It takes about an hour to travel from the marina on South Padre to the Clipper. Water and soft drinks available on board, and the staff help divers gear up on the back deck. From there, it's an easy forward roll into the water. Exit is by rear ladders, again with assistance from the crew.
Diving Nitrox at the Clipper is highly recommended, and American Divers will train divers who are not Nitrox-certified before the trip.
Other highlights of Dive Week include free burgers and beer at the Sea Ranch Marina dock following the dive trip, HID light and rebreather demonstrations, presentations by South Padre Island's Sea Turtle Inc, t-shirt and equipment giveaways, and special deals on hotels and dining. Ten percent of all proceeds from Dive Week will be donated to the Soldiers Undertaking Disabled Scuba (SUDS) program, which is dedicated to helping soldiers returning from Iraq and Afghanistan by taking them diving.
To reach the marina, take a right off the bridge to the island, go one-third mile and turn right into the parking lot. Sea Ranch Restaurant shares the parking lot, offering waterfront seafood dining and bar.
South Padre Island Dives
American Diving regularly offers dives to other wrecks and rigs in the area, including Little Sara (10 - 100 feet), Seana's Rig (10 - 100 feet), Liberty Ships Reef (50 - 100 feet), The Albatross (80 - 105 feet), Dona Nelly (80 - 130 feet) and The Godfather (80 - 136 feet). Around the rigs, barracuda, jellies, and large schools of fish are common sights. The Iron Reef and Little Sara are also available as snorkel trips. Call 956-761-2030 for scheduled dates and to make reservations. All gear and equipment is available to rent at the shop.
In addition to diving, South Padre Island is known for kite boarding, surfing, jet skiing, parasailing, fishing, and dolphin watch cruises. Schlitterbahn Beach Waterpark offers more than a dozen slides, chutes and other water rides, with an on-site restaurant and access to the beach. The South Padre Island Birding and Nature Center is one of nine World Birding Center sites in the area.