There will be pigs flyin’ and hell freezin’ before you find me in a pool with a bunch of naked strangers. It’s not so much modesty as the yuck factor, and I don’t mean appearance-based, I mean kindly keep your pubic hair to yourself.
I can get as naked as the situation demands, including locker rooms and changing rooms for performances (some of which have been co-ed; you just keep your eyes to yourself). And I’ve had the whole “drunk skinning dipping” experience, but once the ooh, we’re so naughty! factor wore off, I realized I’d have more fun swimming with a suit on (drunk or not) because then I wouldn’t be so self-conscious.
So one more vote for a big “NO” to casual nudity with anyone except a SO.