F.K.K. = Freikörperkultur = free body culture
Nudity is less of a deal over here. Nudity beaches are easy to find, and unlike in the U.S., mixed nudity beaches exist. Places such as Teufelssee (which I visited) had nude people as well as clothed people and nobody made a fuss. Nobody gawked at other people. There was no pressure to strip or to be clothed. You could go for a nice swim. Or you could sit and read a book. Either clothed or unclothed. Or you could just go tan without worrying about tanlines. It was wonderful.
Some stuff I learned from going to the beach and also from the internetz.
do not take pictures without permission
do not stare. (this would be rude even if someone were clothed)
if sitting on a public seat, have a towel if you're nude
do not harrass/touch people. this is not a place to hit on people and people will not appreciate it. if you automatically sexualize naked bodies instead of treating them like they are, you are not mature enough to go to a nude beach
Pros of swimming naked in a lake
no gross wet clothing feel
no nasty chlorinated water
people can't see your body under water anyway so it doesn't matter that you're naked
other people are nude so it's not like people are here to judge you
My professor told me this factoid about FKK. Apparently part of the reason the nudity movement started was in an attempt for people to get more vitamin D (which is produced automatically by the body when there's sunlight). It wasn't some weird sexual thing. It was literally a health reason.
Reading the comments on the internet, which were written by mostly Americans, made it clear that Americans tend to sexualize unclothed bodies. The amount of comments I read that said stuff like "nude beaches are sexy" or "bring a partner to go with ;)" or "it's an excuse to ogle that hot chick you didn't stand a chance with" was just mindblowingly annoying. Here's to hoping that in the future, Americans can be more European in the way they treat human bodies. Trust me, it's much healthier.