Long Beach parking area, the divemobile, and the shower in the background

Wetting your wetsuit

There is an often repeated joke that there are two types of diver: those who pee in their wetsuits and those who lie about it. Its true to say that having just paid handsomely for a new wetsuit the idea is not to pee in it. However, sooner or later it’s going to happen to you! This is why….

The physiology

Basically, you can’t help yourself. The physiological phenomenon in question is known as immersion diuresis, a term which refers to your body’s response to being under pressure. Blood is shifted to your body’s core because of the cold and pressure on your body, which increases your blood pressure. The hypothalamus gland thinks this means your total fluid volume is too high and tells your kidneys to make urine.

What can you do to avoid immersion diuresis? Avoid diuretics like coffee and other caffeine-rich drinks before you dive! Intentionally not drinking any liquids  might seem like a sensible idea, but dehydration predisposes you to decompression sickness and saps your energy.

Try to stay warm. A by-product of your body’s reaction to cold is urine. Wearing a warm chicken vest under your wetsuit may save you from having to empty your bladder while underwater. Make sure you have good gloves, thick booties and a decent hoodie. On the boat, stay out of the wind if you can, wear an anorak and a beanie or cap.

Be sober, healthy, and well rested. Some over-the-counter and prescription medications can interfere with your body’s heat conservation activities, typically by hindering the constriction of blood vessels near the skin. Antihistamines, taken for hayfever and other allergies, are particular culprits as is alcohol. Make sure you are physically fit.

How to avoid it

What can you do to prevent urination on a dive? Drink less water? The counter-intuitive answer is that you should drink more.

Deliberately dehydrating yourself, in the hope you can hold it until you surface and get out of your suit, just makes the problem worse. Because of immersion diuresis and your body’s involuntary reaction to the chilly water, chances are you’ll have to pee anyway. And dehydration makes the result stronger in odor and colour.

If you do have to pee in your wetsuit…

If you’re well-hydrated, your urine will be almost clear and nearly odourless. So it can be your little secret.

There’s no health risk to urinating in your wetsuit. If you’ve watched Survivor or read anything about treating stings from jelly fish and bluebottles, you may recall that urine is sterile, unless you already have a urinary tract infection. The worst you have to fear is a case of nappy rash if the urine stays against your skin for a long time, and this is much less of a problem when your urine is diluted.


The solution is to open your wetsuit under water and rinse it between dives, if you can stand the rush of cold water. If you’re at Long Beach for a training dive, there’s a conveniently located shower in the parking area!

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Scuba diver, teacher, gadget man, racing driver, boat skipper, photographer, and collector of stray animals

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