Back when I was in the process of getting my basic certification, a diver friend told me there are two things every diver gets used to:
- Spitting in their mask
- Peeing in their wetsuit
I am told by my spouse that this is something familiar to swimmers as well (substitute goggles for mask and swimsuit for wetsuit).
Update: Peeing in your wetsuit makes it smell absolutely horrible after a while, unless you periodically rinse it in diluted chlorine water, for example, in a pool.