Lesson 42

Lesson Three: Staying Warm

Course Complete

Learning Objectives

By the end of this section, I should be able to answers these questions:

1. Why do I chill faster in water than in air at the same temperature?

2. What do I do to stay comfortably warm while diving?

3. What should I do if I’m not warm enough while diving?

4. What should I do if I start shivering uncontrollably?

Staying Warm

Water absorbs more heat than air of the same temperature, and absorbs it about 20 times faster. This means you can chill rapidly even in water as warm as 30ºC/86ºF. Without an exposure suit, you will get cold after a while, though you may stay comfortable long enough to enjoy a dive.

To stay comfortably warm while diving, you choose an appropriate exposure suit – a wet suit or dry suit – to insulate you. Generally, you need one when diving in water 24ºC/75ºF or cooler, but even in warmer water most divers still use an exposure suit.

The type of exposure protection depends upon the water temperature and how long you plan to dive (or be in the water).

Dry suits provide the most insulation. You use these for the coolest water/longest dives.
Wet suits allow diving in a wide temperature range because you can choose different thicknesses, and select styles that cover more or less of your body.

If you are not warm enough while diving, end the dive and use more exposure protection next time. It makes no sense to keep diving if you’re not enjoying yourself. With the proper exposure suit, you don’t have to get cold while diving – even in relatively cool water.

Hypothermia

Exposure suits work very well, but in all but the warmest water you still gradually lose heat. You may be insulated for most of the dive, but if you are in the water long enough you will eventually get cold. Normally, you’ll end the dive if you start to get too cool for comfort. However, be aware that if uncontrollable shivering begins, it is a sign/symptom of hypothermia.

Hypothermia is a serious condition in which your body cools so much it can no longer function properly. If you begin to shiver continuously, exit the water immediately, dry off and seek warmth.

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