Contrary to popular belief, everyone sneaks a quick one off when they're diving. Even if they say they don't, they lied. Well here's some scientific study that says "hey, it's ok to pee in the sea". Just make sure you scrub your suit from time to time. Hot climates and urine soaked dive kit get very smelly, very quickly...........
"Again, back to Jones: “The key thing here is that urine is continuously
excreted into our natural environment by billions of creatures across
the globe, much of it winding up in oceans eventually in one form or
another, but this process is perfectly natural. Indeed, it is essential.
Without the fertilizing effects of urine nitrogen, many plant species
could not survive.”
So there you go, have at it and pee like you've never pee'd before!