Snorkelling Techniques

The following are techniques to make snorkelling enjoyable, safe and fun.

Clearing the Snorkel

Clearing the water in the snorkel after swimming below the surface is the main issue a snorkeller must deal with.

The principle is to blow the water out of the snorkel on surfacing, while keeping the face looking down into the water.

The best way to do this is by tilting the head at an angle as the head breaks the surface. This is best done by looking at the surface as the snorkeller surfaces. Then as the snorkel breaks free into the air, a quick blow from the lungs will clear the snorkel.

Doing this at an angle doesn’t require as much effort as when the snorkel is pointing straight up as the water in the snorkel is not as heavy.

Surface Diving With a Snorkel

There are two main ways to get underwater when snorkelling.

1.The pike, or duck dive. The snorkeller on the surface, bends in the middle so the head faces down; then the arms pull the body down. The fins don’t start kicking until under the water to prevent the wild thrashing of the fins on the surface.
2.The feet-first dive. First the snorkeller fins straight up so the body is high out of the water, then sinks straight down. Once under water, the snorkeller rolls into a ball, tucking the feet up until the head is facing into the depths. Again the hands pull the body down and the fins don’t start kicking until clear of the surface.
Ear Pain While Snorkelling

Ear pain while snorkelling is caused when a snorkeller descends creating a pressure difference across the eardrum between the outer and middle ear. This forces the eardrum to bulge inwards causing increasing ear pain until eventually the eardrum will burst.

Equalisation of the pressure difference is achieved via the eustachian tube that connects the middle ear and the throat. The tube must open to allow the higher pressure (in the throat) to flow into the middle ear.

The eustachian tube is kept closed by small muscles in the throat. To open these muscles, the snorkeller must yawn, swallow or move the jaw.

Sometimes opening the eustachian tube is not enough and a snorkeller may need to force air up the tube. The snorkeller pinches the nose and blows against the closed nose and mouth. This equalises pressure across the eardrum and is usually referred to as the ear “popping”.

Called the “Valsalva” technique, it is named after a scientist in the 18th century.

It must not be forceful as the eardrum can rupture.

Snorkelling in Tight Places

For some snorkellers there is temptation to swim through caves, under ledges or into wrecks. This can be fun and challenging, but there are risks involved.

•a piece of clothing could get caught;
•a serious knock on the head on a narrow space;
•or maybe an encounter with fire coral.
These risks can be minimised, but not eliminated, by having a snorkelling buddy watch over these activities.

Snorkelling Hyperventilation

A common practice for snorkellers is taking long, deep breaths (hyperventilate) just prior to ducking under the water. This can prolong the time on the one breath.

Hyperventilation increases oxygen and decreases carbon dioxide in the body. This is acceptable for a few breaths, however prolonged hyperventilation can reduce the carbon dioxide in the body to levels where the acid-base balance of the blood is disrupted. This is called hypocapnia and can lead to unconsciousness.

Snorkelling hyperventilation should be limited to just three or four breaths.

The above snorkelling techniques should lead to safe and enjoyable snorkelling.

Carbon Monoxide Poisoning and Scuba Diving

Carbon monoxide is a tasteless, colourless and ordourless gas formed by the burning of petroleum based fuels in combustion engines; and the burning of plastics, coal, and cigarettes.

How Does Carbon Monoxide Affect a Scuba Diver?

Red blood cells contain haemoglobin that attracts gases. Live-giving oxygen is the main gas the haemoglobin “latches” onto. However, carbon monoxide is also easily absorbed by haemoglobin; and binds to the haemoglobin around 200 times stronger than oxygen.

What this means for a scuba diver breathing from a contaminated tank, is that the blood can quickly become “overloaded” with carbon monoxide. This cuts out the oxygen and means the oxygen does not get to the body’s tissues where it is needed to make the cells function correctly.

The result is carbon monoxide poisoning.

Carbon Monoxide Poisoning Underwater

When a scuba diver is underwater with carbon monoxide poisoning, the haemoglobin may be overloaded with carbon monoxide and can’t absorb much oxygen. However, the increased partial pressure of oxygen at depth may result in enough oxygen in the blood to keep the cells oxygenated.

In this situation the diver can function, but when they ascend to a shallower depth, the partial pressure of oxygen will decrease. This will lead to the tissues being starved of oxygen and unconsciousness can occur.

A scuba diver with carbon monoxide poisoning will probably feel unwell while underwater, so should ascend as soon as symptoms occur.

How Does a Scuba Diver Get Carbon Monoxide Poisoning?

One the most common ways for a scuba diver to get carbon monoxide poisoning is from the scuba tank being filled with air contaminated with carbon monoxide.

This can occur if the fresh air intake pipe to the air compressor is next to a source of carbon monoxide, such as the exhaust of the engine driving the compressor.

In some situations, a well-meaning dive shop operator may have the air input pipe to the compressor outside in the fresh air. However, a car with its exhaust running might pull up close to the intake and its carbon monoxide may find its way into the tanks.

Careless location of a compressor’s air intake on a boat can also result in carbon monoxide from the boat’s engine.

How Does a Scuba Diver Avoid Carbon Monoxide Poisoning?

A scuba diver can reduce the possibility of carbon monoxide poisoning by having a quick check of the location of the air intake of the air compressor when getting a scuba tank filled at an unknown filling station.

This is especially important when on a scuba dive holiday.

As carbon monoxide is contained in cigarette smoke, a scuba diver shouldn't have a cigarette just prior to ducking underwater.

Symptoms of Carbon Monoxide Poisoning

The most common symptoms of carbon monoxide poisoning are:

•Cherry-red lips, cheeks and fingernails;
•Dizziness;
•Headaches;
•Staggering;
•Confusion;
•Paralysis.
Unconsciousness and death can result.

Treatment of Carbon Monoxide Poisoning

The first aid treatment for carbon monoxide poisoning is fresh air. This should be in the open deck on a boat; not inside the cabin or near the engine’s exhaust.

Pure oxygen should be administered, if available.

A check up at a hospital or doctor is always advisable for any diving related medical condition; even if the symptoms are mild.

Fortunately carbon monoxide poisoning is rare. However, its impact can be reduced by a scuba diver’s vigilance in being aware of the scuba tank filling station’s procedures.

Scuba Diving Tweed River, Australia's Gold Coast

Nearly every weekend, scuba divers can be found at the Tweed River dive site, either doing scuba dive training or simply enjoying getting under the water

Location of the Tweed River Dive Site

The Tweed River dive site is located on the northern bank of the Tweed River, about 500 metres from the river mouth. There is a car park and a large grassed area; perfect for gearing up and pre-dive briefing.

Access to the water is via short scramble over rocks then onto a concrete platform where the water laps at high tide. This concrete platform has been built over the years by various scuba divers and scuba dive schools and now provides an easy access and exit location

The GPS coordinates (Decimal Degrees) for the Tweed River Dive Site are:

-28.169644

153.549213

When to Dive at the Tweed River Dive Site

The best time to do a shore scuba dive at the Tweed River is on the turn of the high tide as the dive site is impacted by tidal flows. For a forty minute time underwater, entry should be about twenty minutes before the high tide.

Diving on the change of tide is also the optimum for the best visibility underwater.

Details on the Tweed River Dive Site

The Tweed River dive site is not known for good visibility. Its attraction is mainly for scuba dive training courses and an easy place to simply get wet on a scuba dive.

The maximum depth is around 40 feet; with visibility usually around 20 to 30 feet.

The ease of access makes Tweed River dive site especially good for initial training in night diving. The easy entry and exit, and gear up area means a night dive can be conducted in relative safety.

What’s to See at the Tweed River Dive Site

The Tweed River dive site has some unique aspects. For many years, an old bath-tub was a common feature at the bottom. Many divers in South East Queensland would have done basic training like mask clearing and buddy breathing around the Tweed River bath-tub.

Soft corals cover the rocks on the Tweed River bank. Schools of bream wander through the dive site, and the occasional octopus can be found lurking under rocks on the bottom of the river.

One diving activity at the Tweed River is to collect sinkers. The fish life attracts fishermen who cast their lines from the riverbank to try their luck. With the rocks on the bottom, there are many snags which means the hapless fisherman loses his or her tackle. This makes it possible to collect a large amount of sinkers for making into scuba dive weights.

Safety When Diving at the Tweed River Dive Site

Because the Tweed River dive site is in a river, there are always a number of boats in the area. This means a dive flag should always be used.

Some training schools will establish a stationery dive flag floating above their training dive. Divers have been known to drag a dive flag along as they swim; the dive flag floating above on the surface while they explore underwater.

Many experienced divers don’t like scuba diving at the Tweed River dive site as they claim it is boring and uninteresting. However, when considering the advantages of the Tweed River; such as easy entry and exits for shore diving, safe conditions and its location on the southern end of Australia’s Gold Coast, the Tweed River dive site is more than just a scuba dive training site.

Scuba Diving at McKenzie Jetty, Australia

The jetty was originally built in the early 1900s to facilitate taking timber off the island to the mainland. A timber mill was built on the island near the jetty and a small railway brought the trees to the mill to be processed and then onto the wooden jetty to be loaded onto ships.

The timber felling ceased in the early 1990s when Fraser Island was declared a World Heritage Area; and Mackenzie Jetty fell into disrepair.

Location of McKenzie Jetty Dive Site

Mackenzie Jetty is an interesting and unusual scuba dive site. The remains of the jetty now are just the solid wooden piles.

The jetty is about 2.5 kilometres south of the Kingfisher Bay Resort on the shores of Hervey Bay.

The GPS coordinates for McKenzie Jetty are:

-25.406885

153.012182

What’s to See at McKenzie Jetty Dive Site

There is not a great deal of interesting fish life to see at the McKenzie Jetty dive site. The main attraction is for scuba divers who like to fossick around old structures looking for interesting memorabilia. There is the possibility of turning up some old bottles, maybe some decayed pieces of machinery, and lots of pieces of old timer. According to John Wright in “Diving Southern Queensland”, in 1988 a scuba found a chamber pot dating back to the turn of the century. As this was once a popular fishing spot, there is always the possibility of getting a bunch of sinkers for making into scuba dive weights.

When To Dive at McKenzie Jetty Dive Site

The waters around the McKenzie Jetty dive site are subjected to large tidal movements. The dive site is also just across Hervey Bay from the mouth of the Mary River. This results in two main problems for scuba divers; poor visibility and strong currents. Therefore, the optimum time to go scuba diving at McKenzie Jetty dive site is just before the high tide. This means the flow will start easing and may improve the visibility.

The wind must be from the east, so that the large landmass of Fraser Island protects the McKenzie Jetty dive site from the wind. If the wind is from the west or north, the visibility plummets and it just isn’t worth getting in the water.

Details on McKenzie Jetty Dive Site

McKenzie Jetty dive site can be accessed by boat from Hervey Bay. Or it can be accessed from Fraser Island. If diving from a boat, the optimum location is about 20 metres south of the last piles poking out of the water. The jetty curved to the south and these remains are in the deepest water, of around 20 metres maximum.

Doing a shore scuba dive takes a bit more organisation, as tanks and scuba gear must be transported along Fraser Island’s rough sand tracks. However, the advantage in diving from the shore is the ease of walking off the beach into the water and following the old piles of the jetty into deeper water.

After diving at McKenzie Jetty from the shore, another unique site is to scuba dive in Fraser Island’s most famous freshwater lake: Lake McKenzie. This is a short drive from the jetty, and provides an opportunity to rinse the salt water off the scuba gear.

For scuba diving in Hervey Bay, McKenzie Jetty dive site provides a unique and interesting experience. It is different from the other scuba dive sites found in South East Queensland and may even provide a glimpse back into a time capsule of the early logging days.

Entry and Exit for Shore Scuba Diving

The entry and exit when shore scuba diving can present greater risks than breathing compressed air underwater on a scuba dive.

Checks Before Shore Scuba Diving

The shore scuba dive site must be checked before venturing into the water. Some scuba shore dive sites are regularly dived, so there should be reasonable general knowledge about the scuba shore dive site.

Boat movements should be checked before entry. It is not good to share scuba dive sites with speedboats, from a safety point of view as well as the noise and waves from the boat wash. A scuba dive safety flag should be displayed

Preferably there should be a suitable area to gear up the scuba equipment. A flat area next to the entry and exit point is best.

There must be something to see or do at the particular dive site, with an adequate scuba dive plan.

Shore Scuba Diving Entry and Exit

The entry and exit points for shore scuba dives must be considered carefully. They could be slippery or unstable that will present a risk when waddling in scuba gear on the land.

At the end of the scuba dive, the exit point might become slippery with water dripping off divers.

If the water is a bit murky and what is under the water in the first few feet can’t be seen from the bank, then it would be best to slide in feet first. A giant stride entry into murky water that hides a sharp tree stump is not good.

Second Exit Point When ShoreScuba Diving

A second exit point should be determined before getting in the water. The current should be checked for the direction of travel. Then if something goes wrong during the scuba dive, the second exit point could be used.

Scuba Surf Entry

Scuba diving through the surf can be an interesting and challenging experience.

The best time to enter the surf, say to dive on a reef or wreck outside the breakers, is when the surf is small. If the surf is large, the bottom will be stirred up making poor visibility.

Rips should be avoided. This is where the water returns to the sea. Rips are characterised by breaking waves being reduced and looking “confused” by the large amounts of water flowing against them.

Before heading out, a compass bearing should be taken on the reef or offshore dive site.

Scuba dive fins should be put on before entering the water and then the diver walks backwards into the waves. A scuba diver should get below the waves as soon as possible as it is much easier to swim below the water than on top. It is also fascinating to watch the waves breaking above the head while swimming out.

The compass should be used for direction as the sandy bottom under surf usually has nothing for reference. When at the dive site, a marker should be placed as a reference point for the start of the return swim.

Scuba Surf Exit

The procedure for the scuba surf exit is similar to that for entry in that a scuba diver should remain under the waves for as long as possible.

When safe to stand up, that is between waves, the scuba diver should walk backwards out of the water and onto the shore. Fins can be removed when out of the waves.

Shore scuba diving can be fun and also provides an opportunity for exploration. Scavenging for bits and pieces such as historic bottles or fishing sinkers to make into scuba dive weights can make shore scuba diving a rewarding dive.