How to... dive in cold water
Rolling off a boat at Ras Mohammed, at day break, into a glass calm 28°C Red Sea is pretty close to heaven in my opinion. The trouble is, unless you work there, this treat is all too rare. Usually you get to the airport, not having had a holiday in eons, trying to remember where and when you went diving last.
You start the week feeling a bit of a prat as your Divemaster, patience personified, points out that your regulator will work much better if you turn your air on before you get in the water. After five days these elementary errors are behind you and there you are, a picture of serenity, motionless at one with nature. On day six you're in the airport again on your way home.
Instead of returning home to hang up your fins and get out of practice again why not take the plunge into cold water? Yes, I know it's December but diving is an adventure sport; get out there!
Of course you may be put off by more than the rain and sleet. Horror stories abound about regulators freezing and free flowing. It's true, there is not a regulator on the planet sold with the express guarantee that it won't freeflow in cold conditions.
This is what Scubapro says about diving in cold water (less than 10°C): “Diving in cold water requires special equipment and techniques. Before attempting a cold water dive, obtain adequate training from a recognised certification agency”.
Scubapro and other manufacturers design regulators for use in cold water that are rigorously tested. However they have no control over the way in which you look after and use your gear, which is where training comes in.
Understanding both your limitations and those of your gear is vital. Any condition that leads to an increased breathing rate will also increase the risk of regulator free flow.
Diving in cold water is as much about planning to take account of your limitations as the kit. If you want to give it a try – talk to your instructor and organise a dive. Diving in cold water can be warmer than you might think and you'll feel so much more confident when you are next in the Red Sea.
Top Tips for Cold Water Diving
1. Use a dive suit that's up to the job of keeping you warm. Leaky drysuit seals cause nuisance at best and stress at worst. Using a semi-drysuit is not out of the question but guard against wind chill by wearing a wind-proof jacket over your suit.
2. When was your gear last serviced – your regulator especially? Some manufacturers have specific cold water set up procedures for their regulators so consult your dealer.
3. On the day aim to start warm and stay that way. Eat properly and avoid alcohol in the 24 hours prior to the dive. Don't take a jacket and hat to put on when you get cold – it's too late then. Wear them to prevent heat loss.
4. Prepare your gear at home in the warm and dry so that you have minimal preparation to do on site. At the dive site try to keep out of the wind as much as possible. If you start the dive feeling cold and miserable you won't be calm and relaxed in the water.
5. If you exert yourself before getting in the water, give yourself a few minutes to rest, relax, and 'visualise' the dive. You need to be able to start the dive completely calm and in control of your breathing.
6. Don't use the purge button of your regulator on the surface and don't breathe from the regulator until you are about to descend. Discharging air at the surface can cause a very significant drop in temperature inside your first stage quite possibly leading to a free flow.
7. Make sure that you are weighted properly. If you cannot easily achieve neutral buoyancy your breathing rate will probably be higher than it ought to be.
8. In particular, don't overweight yourself. During the descent, if you have to put a lot of air in long bursts into your drysuit or BCD you will cause greater cooling of your first stage.
9. On the bottom, minimise your exploration so that you swim with minimal exertion.
10. Limit your depth and duration so that you are out of the water before you start shivering. Remember also to make allowances for decompression. Some dive computers will take account of cold water but not all. The PADI RDP recommends adding 4m to your depth for working out pressure groups.