Dive Article written by Compass' mermaid Restuning Sandini as published in GuidePost Magazine
Emptying the bladder is a sensitive topic for divers, we all know we have this urge during our dives but we all don’t want to talk about it. Hence a divers’ favorite joke: “There are two kinds of divers. The ones who pee in their wetsuits, and the ones who lie about it. “
Years ago, one of my students bought a new custom-made wetsuit. She declared theatrically before the dive: “In this one, I would never ever pee”. You guessed the outcome. A tragedy of the new wetsuit.
But why is it?
Why, do we need to pee when we dive? Why - despite of all your motivation of not to - you have the irresistible urge to release the bladder when you dive?
Say hello to immersion diuresis. In principal it is how the fluid (blood, water, electrolytes) shift in our body – a result of reduced effects of gravity - and triggers the kidneys to produce urine. Also known as Gauer-Henry Reflex. On land, due to gravity, a fair portion of our blood is located at our arms and legs. After that back-roll entry, as soon as we hit the water, we lose this gravity and the fluids in our body move from our limbs to our thorax. This is registered as having too much fluid and our body wants to relieve it, so a signal is sent to the kidneys to produce urine to flush this out. The kidneys respond and fill up the bladder. When you’re back on the boat, and back to gravity, it is too late, the bladder is already full. This is actually an awesome body reflex; We experience what the astronauts feel!
Temperature also plays a part in this. Even when diving in warm Timor-Leste water, after 45 minutes, you might get cold. When we are cold, we try to conserve heat and lower the temperature of the arms and legs. This too will bring extra blood in the chest and our body will order kidneys to produce more urine to flush this out.
So now you know, it is normal to have the urge to pee in your dive. You can’t fight it. Don’t drink less water to avoid it. Getting dehydrated during a dive is a more serious issue. Just jump in the water and clear your bladder before wearing your gears. This usually will give you long enough dive time before you cannot hold it any longer. And yes, there is a signal for “I need to pee” and “Oh, I can’t hold it any longer”. Listen to my briefing.
Happy bladder, happy diving!!
Unieng*And just for the record: I don’t belong to any of those two types of divers. I don’t wear wetsuits. Ha!