Perhaps it's more of a YC "party atmosphere" thing than a sailing thing?
Oh, I'm all about the party -- but there's a big difference between joking around in public when everyone has a G&T in hand, and a married man making schmoopy eyes and inappropriate suggestions when he's crewing for me. Yuck.
A few solutions have come to mind: the unannounced jibe (oh, I've been tempted); finding women to sail with (not easy here, since the few who sail, sail with their SO); or limiting crew to single men, from whom the occasional schmoopy look might not be unwelcome (ok, so where are they?).
Sad-but-true moral of the story, I guess, is that guys on boats -- even sailboats -- behave badly; and a girl should be prepared to deal with it.