Saturday 23 January 2016

How to dive a drysuit

Too many Cooks spoil the Broth...Many hands make light work

He who hesitates is lost.... Look before you leap

Practice makes Perfect... All work and no play makes Jack a dull boy.

These are just some examples of how simple everyday advice can conflict and confuse. We learn these proverbs from an early age and if you think about it, each one has another in place to contradict.

In the same vein, there are 2 very contradictory ways that divers are are taught to dive a drysuit.

A drysuit is essentially a sealed bag that we wear when we go scuba diving in colder waters. It prevents water from contacting the majority of our skin and therefore, alongside thermals, keeps us warmer than would a wetsuit.

When we go deeper underwater and the ambient pressure increases, the air inside the drysuit (like in all air spaces) compresses and unless we add air, via an inflator usually found mid chest, the suit begins to squeeze our bodies, becoming uncomfortable.

Equally, as we ascend, the air we have added to the dry suit expands and we have to be able to remove this air to control our ascent. This is usually done via a "dump valve" found on the arm or wrist.

Pretty straight forward I hear you say... where is the confusion? This comes from the way certain divers are taught to use their dry suits.

Many divers are taught that, when using a drysuit, this will become their primary means of buoyancy. This means that, rather than using the BCD or wing, everything is controlled with the drysuit. The premise of this appears to be that one set of buoyancy to control is easier than 2 lots of buoyancy. If something goes wrong and there is an emergency, it is easier to only have to concentrate on one set of buoyancy control and since we have to add air to the drysuit on descent, this is the winner.

However, with that much air in your drysuit, you will find that you get air bubbling out through the seals. Even if you are correctly weighted, you will have this problem and if you are overweighted, you will be bubblier than a glass of Champagne at New Year!

The result is constant re-adjustment of buoyancy as air is lost through the seals. You may also find it extremely uncomfortable, as there is more air moving around inside the suit, which can lead to less control in the water.

It is much more effective to just add enough air to the drysuit to take off the squeeze and then use your BCD to control buoyancy, as you would in a wetsuit. You will find that you should have much more control over your positioning, buoyancy and trim.

If you don't dive a drysuit this way already, give it a try and see the difference.

After all... Actions speak louder than words!

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