I gotta say I like the casual non-date atmosphere for quickly hooking up with chicks. During the past two summers, after I have a few girls and numbers to choose from, I call one up and since where I live there's not much to do, it's easy to be like come over to my place and we'll figure out what to do from there. Usually on the phone she'll be like hmm we could do this or this or that, and I'll be like ehhh I duno why don't you just come over and we'll figure something out, or it's so hot out today come over for a swim. Most of the time I'm already drinking some ****tails or wine on nice summer days, so when a girl arrives she usually indulges. Couple ****tails/glasses of wine + pool = hooking up easy. I guess the alcohol factor could implicate me as a taker-of-advantage, but nobody gets housed so whatever.
Sidenote: I think bodies of water are an awesome tool for hooking up with girls. Jet-skiing=her wrapped around you, the rush from acceleration and speed, girls love it. Pools=playing like little kids as the physical proximity escalates, sounds childish, but splash fights and cannon-balling her easily leads to some wrestling and that easily turns into making out, etc etc. Beaches & ocean=easy hook up spot.