The sun has long set on those balmy days of summer diving and as the festive season holidays approach, there are still some of us who enjoy the thrill of the chill. The dive plan must then reflect that the aim is to enjoy not the thrill whilst avoiding the chill.
So lets examine some ideas to ensure you can enjoy the cold-water blues.
- Cover your head, heat loss through the head can account for forty percent of total heat loss, whilst a lot of divers enjoy the freedom of bare headed diving in summer, for winter the hood or diving beanie should be considered compulsory and not an accessory. Check though to ensure the fit is snug and not choking you, like the layering of wetsuits try wearing two thinner hoods rather than one thick hood.
- A Wetsuit is just what the name implies, you will get wet. But the aim is to trap a fine layer of the water and not provide a water sluice. Check the fit is right, whilst the comfortable wetsuit you use in summer has a neck seal that is best described as dodgy, consider hiring a good wetsuit for those couple of winter dives.
- Consider investing in dry suit if the cold bug takes you – the sooner you do and get the proper training the longer the dive season becomes.
- That three quarter length 5 mm shorty may be good for summer but a complete no go for cold water, a good thinner full length suit will provide more warmth than a shorty.
- Shallow water equals warmer water, no not because of thermoclines but due to wetsuit neoprene compression. The deeper you dive the thinner the neoprene and hence the loss of warmth. Plan winter dives to maximise comfort.
- Layering can also enhance the joys of cold water, most good 5mm wetsuits will ensure a comfortable dive in most dive spots of the world to offset the cold consider a 2 or 3mm vest with a built in hood, this is a great way to avoid having to buy a 7 to 9mm wetsuit for those winter dives.
- Be wary of Manufacturers claims of miracle fibres and layers of material as used by Astronauts, it comes down to the simple matter of quality neoprene and a suit that fits.
- The Surface Interval is often the time when divers really lose core body warmth and not whilst in the water. That cold wind blowing over our wet wetsuit is basically sucking the warmth out, if possible get out of the suit, dry off and put on some dry wind proof clothes and a wool cap. No diver ever likes getting back into the cold wet wetsuit but you will be much warmer and the risks of hypothermia will be greatly reduced.
- Shivering is often the first indication of hypothermia – so take it as a warning, surface, get out change into warm clothes. Hypothermia is something that should not be taken lightly.
- The risk of DCS is also greater in cold water – so plan accordingly, reduce depth and bottom time Nitrogen is more soluble in cold water and high levels will dissolve into cold tissues. The distribution of nitrogen will also be affected as blood vessels constrict due to the colder temperatures
Enjoy the challenge, and for those enjoying summer in the Southern Hemisphere. Remember winter is not far off.