My first skinny dipping experience was rough (co-ed participants + uncontrollable raging hard on = trauma), but I've loved it since then.
A few years ago I rented a beach house with a bunch of men and women. One afternoon we made a pact to meet at the beach at midnight to skinny dip. The anticipation and crowd grew as we went from party to party that night. The main event did not disappoint -- there were tits and cocks bouncing everywhere.
A few other nights we'd be hanging out on the beach and spontaneously decide to jump in the ocean, but those ended up being sausage fests with the men on display for the women. The women would sometimes return the favor, though, with afternoons of topless sun bathing.
As we head into Memorial Day weekend, I wish everyone a summer full of skinny dipping!