Why does diving make you pee so much? From beginners to ocean explorers we all have to pee more when we are scuba diving. Then there is always the question to pee or not to pee? Will anyone notice? What about my poor wetsuit, will it ever forgive me?

We have a stance in the scuba diving industry that there are two types of people:

1. Those that pee in their wetsuits and admit it
2. Those that pee in their wetsuits and lie about it

Why Does Diving Make You Pee

The unofficial hand signal for “I need to pee!” this sign followed by a splitting of the index and middle finger means “I am now peeing!”

Some might think that is disgusting, but actually it isn’t really if you maintain your wetsuit properly. Think about it. The “marine toilet” is just a fancy name for a hole in the boat. Your donations go right out to sea and that is the same sea you then swim in minutes after.

What about the economical factor? No need to flush when we are in the ocean already!

And thirdly, peeing in your suit can actually help to keep you warm for a little bit longer.

Woops I did it again.

It happened, you could not hold it and you had to pee in your suit. What do you do now? Ever noticed other divers jumping back off the boat and flailing about on the surface with their wetsuit half way down? Yeah, that’s flushing. What about that guy you watched hanging upside down on the dive and purging his alternate air source into his wetsuit? Well that is a tricky one to execute, but is also flushing.

When you get back to the dive shop, you should always rinse your suit in fresh water and then give it a bath in some anti-bacterial soap.

It is just part of diving sometimes.

So, now that we have established that you are not a freak because you have to pee more when diving and it is actually very common, here is some science in layman’s terms to explain why.

Immersion Diuresis

Even when we dive in warm water, unless it is identical to our core body temperature of 37 degrees celcius, our bodies are working to keep us warm. Unless you dive in a spa, you will get colder over time while submersed. This is natural. Some people feel the cold more than others and their body reacts by pulling blood from the extremities and focusing on keeping more blood, so warmth, near the heart and other vital organs. Our body being quite amazing, senses this increase in blood pressure near the core and interprets this as too much blood or water in our system. This sends a very efficient messenger down to the kidneys with the order “Dump some fluids!” And that is when more urine production is initiated.

Going Under Pressure

Awesome, we jump in and are descending again. As you know we add significant pressure to ourselves when we scuba dive. 1 bar of pressure for every 10 meters. Our body senses this increase in pressure mainly due to capillaries in our extremities being compressed, forcing blood towards the core of our body. Remember what happens when that increased pressure gets noticed by the body? Well it is time to send that messenger back down to the kidneys and we pee again!

Defying Gravity

Possibly the coolest part of scuba diving is when we feel that weightlessness by defying gravity. Because we are in less pressure we feel the effects of gravity more on the surface as opposed to being in a liquid. Gravity actually pulls blood into our arms and legs, keeping the pressure lower in the core of the body. Now when we are in the water, especially once we are neutrally buoyant, we significantly reduce gravity’s effect, so our blood is more evenly distributed in our bodies. This means that pressure still slightly increases in the core and guess what? That messenger better put his lunch down to leg it down to the kidneys once more and order urine production.

We do definitely not recommend drinking less or taking any type of medication to reduce urine production levels. It is a natural reaction of our bodies and is actually kind of cool now that we know why.

In fact drink loads of fluids when diving to increase hydration levels.

Now, please excuse me, I need to go pee.

By Lionel

Leave a comment of your “pee in my suit” story or tag someone you KNOW pees in their wetsuit

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1 Comment
  1. 6000+ dives – peed on the majority of them – just best not to do it on the safety stop so theres plenty of time for it to have flushed out 🙂

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