I will agree with CasperTG and go with swimming or SCUBA.

Didn't the original Greek Olympians play all their sports in the nude? Isn't "Gymnast" really part of the root word "Gymnos," meaning nude athlete or something like that?

__________________
Though dreams can be deceiving, like faces are to hearts; they serve for sweet relieving when fantasy and reality lie too far apart.-Fiona Apple