[skeeter]

Its not necessary for any other than obvious reasons - paddling in, climbing out of the wetsuit and seeking a bathroom is not really an option.

It may be necessary, but I still can't stand doing it.

[driftdiver]

Not to mention when you are down about 80 feet its rather inconvenient to surface just to pee.

besides the pressure shrinks your bladder which make you go pee more.

Fish do it so it must be ok.