To Pee or Not To Pee? The Science of Warming Your Wetsuit

We've all been there. You try to hold it in, but can't. Desperate, you pee in your wetsuit. You hope no one will notice. But what can you do? Drink less water?

No, drink more.

The Dehydration Factor
* Deliberately dehydrating yourself, in the hope you can hold it until the surface interval, just makes the embarrassment problem worse.

* Because of immersion diuresis and your involuntary reaction to cold, chances are you'll have to pee anyway.

* Dehydration makes the result stronger in odor and color.

The Embarrassment Factor
There is a well-worn joke that divers belong to two schools regarding peeing in their wetsuit: Those who do and those who lie about it. If you do have to pee in your wetsuit, know this:

* If you're well-hydrated, your urine will be nearly clear and odorless. Almost like water. So who's to know?

* There's no health risk to peeing in your wetsuit. Most people don't realize that urine is sterile, unless you already have an infection of the urinary tract. The worst you have to fear is a case of diaper rash if the urine stays against your skin several hours, and this too is less of a problem when your urine is diluted. Solution: Open your wetsuit under water and rinse it between dives.

The Warmth Factor
True or false? Urinating in a wetsuit is a quick way to warm up. False, and here's why: You may feel warm initially, but it will actually lower your body's warmth. And, if you're wearing a tight-fitting wetsuit that doesn't flush easily, a semi-dry or dry suit, then this warming-up technique loses a lot of its appeal.

Why do I need to pee so soon after entering the water?
This physiological phenomenon is known as immersion diuresis, a fancy term for your body's response to feeling under pressure. Blood is shifted to your body's core, and the hypothalamus gland thinks this means your total fluid volume is too high and instructs your kidneys to make urine. What can you do to avoid immersion diuresis?

* Avoid diuretics like caffeine before you dive.

* Intentionally dehydrating yourself might seem like a good idea, but dehydration increases fatigue and predisposes you to decompression sickness.

* Try to stay warm. A side effect of your body's response to cold is the production of urine. Wearing a hooded vest under your wetsuit may save you from having to empty your bladder when you least want to. On the boat, stay out of the wind, bundle up and wear a hat.

* Be healthy, sober and rested. A variety of over-the-counter and prescription drugs can interfere with your body's heat conservation mechanisms, typically by preventing the constriction of blood vessels near the skin. Antihistamines are particularly suspect. Alcohol is worse.

* Although adipose tissue insulates well, allowing fat people to tolerate cold water immersion longer than lean people, it's better to be physically fit.


Portions Reprinted with permission from Scuba Diving - The Magazine Divers Trust