Daring Enough to Bare It All for a New York Swim Brandon Venable, 20, from the Bronx, said he initially did not plan on swimming nude - or swimming at all - at Jacob Riis Park. Lifeguards prepared to leave the easternmost tower at Jacob Riis Park beach, blowing shrill warnings to swimmers that they would no longer be watching them that Saturday evening. For most, it signaled the end of a steaming summer day. But for some on land, more than a couple of them flushed from alcohol, it was the declaration they had been waiting for - to rush in, clothing optional. Soon swimsuits hung like ascots around the necks of men and women in the waves. Cheering greeted a man streaking to the surf. Another, more tentative, took off his black underwear in the water, shrieking when his roommate ripped them from his hand and rushed ashore. "Give them back!" he called out. Skinny-dipping, a hot-weather pastime that calls to mind rustic swimming holes and summer camp double dares, has always been strongly correlated with extreme heat and an available body of water. But it is not often associated with New York's miles of densely populated shoreline. Here, an extra level of daring - or, possibly, intoxication - is needed to make the dive. Naked swimmers act quickly under cover of darkness or in permissive pockets of the city: at the gay-friendly patch of Riis beach in the Rockaways or at a marina on City Island where Ivy League sailing teams sometimes bare all; in Bushwick hostel hot tubs or Midtown office building water towers. "It can be a little bit claustrophobic," said Ida Benedetto, 28, of her water-tower dips with co-workers above their media company office. I did this about twice a week for a summer. The city affords a variety of locations where nude bathing is permitted or even required. There are religious bathers in many mikvahs, spagoers in Flushing, and men of means who doff clothes in the rarefied confines of Park Avenue sport clubs. But skinny-dipping is something different, its acolytes say. A term coined in the late 1940s, it connotes both quickness - a dip - and transgression, a departure from the old painted scenes of bathing in rivers. The skinny part, linguists have argued, most likely refers to skin, not thinness. "It's about spontaneity and freedom in the moment," said Lauren Christianson, 23, who along with two partners is working on a guide to skinny-dipping around the city for their Web site, The Skinny Dipping Report. You can't go in the East River or the Gowanus Canal. You have to find these secret spots. One spot eyed for the list, a hot tub at the New York Loft Hostel in Bushwick, may need to be reconsidered. The hot tub was removed last year, a receptionist there said, after becoming an occasional clothing-optional hangout. "Very possibly for that reason," she said. A minor offense most often classified as either "exposure of a person" (a violation) or public lewdness (a misdemeanor), it is not the sort of crime that makes the blotter in New York, as it might elsewhere. Faced with a boisterous bunch of naked swimmers, many officers just shake their heads. "Move along" is more likely to be heard than "You're under arrest." "They were like: "Get out of the water. Oh, and put on your bathing suits," said Ashira Siegel, 35, remembering when a late-night adventure on Coney Island a few summers ago was interrupted by the police. No tickets were issued. "They were just amused, just kind of like, "Yeah, yeah, O.K." Very New York cop," she said. They've seen it all anyways. She said she did not join her friends in stripping down. Near the glowing Wonder Wheel on a recent Saturday night, an officer leaning against a banister said he could count on one finger the number of skinny-dippers he had seen given tickets. "There was a guy today, but that was for public lewdness; a disturbed individual wandered onto the beach," he said, declining to be identified because of the subject matter and a lack of prior approval from Police Headquarters. "Try Brighton Beach," he added. That's where the Russian guys are. But not now. After 5 p.m. or 6, when the lifeguards go home and the families leave, they'll do it.