MARBLEHEAD – The water was warmer than Boston Harbor or the English Channel, and the hungry sharks that colleagues threatened to provide for “motivation” never showed up.But Lynn District Court Probation Officer Kim Garbarino’s swim in the Lynch/van Otterloo YMCA pool this weekend presented other challenges … namely a clock counting every second of the 24-hour-long task.”I felt like it wasn’t moving,” Garbarino said at 6:30 p.m. Sunday, four-and-a-half hours after swimming for 24 hours. “I had them unplug it.”Garbarino, 56, swam from 1 p.m. Saturday to 2 p.m. Sunday (earlier in the week he admitted not remembering Daylight Savings Time when he scheduled the event) to raise money for swimming lessons as part of the Y’s annual campaign. Fellow swimmers could donate to swim alongside Garbarino or could pledge a certain dollar amount for each hour Garbarino was in the pool. Garbarino estimated that he raised $6,000 and has a goal of $10,000 by tonight.Garbarino learned to swim at the Lynn YMCA and recounted early distance swims along Lynn Beach as a kid growing up in the city. Now he swims six days a week either at the Y or off of his current home in Winthrop.He said he believes every child in a coastal community should have the opportunity and so was approached by YMCA management to do some sort of fundraiser. But he credited/blamed himself for the idea to swim 24 hours.Garbarino said afterwards that the 24-hour swim presented different challenges than his previous endurance-distance swims, which have included swimming the English Channel in 2012 and the annual Boston Light Swim.The English Channel, for instance, featured water temperatures in the 50s, tides and currents, weather and a fish who left an inch-long gash in Garbarino’s left foot.”The English Channel was mental and physical; this was all mental,” Garbarino said.The pool was a much more controlled environment than the ocean but, perhaps, too controlled. The only way Garbarino said he could mark progress was by the clocks, counting, or the changing light in the pool area, methods which were either frustratingly exact or too vague.Plus, he said he really wasn’t going anywhere. There was no beckoning shoreline to reach or boat to follow – Garbarino just kept swimming, switching directions every 25 yards. In fact, Garbarino said this constant switching prevented him from getting into his normal stroke rhythm.”It got so monotonous, it wasn’t even my physical conditioning that slowed me down,” Garbarino said.By the 23rd hour of the swim, Garbarino was “still coherent,” as his wife, Amy Simione, said and alternating between a breast and sidestroke as he crossed the pool. But Garbarino said he had lost count of how many miles he had swum after hitting 30 miles (a mile equals about 70 laps in the Y pool) early that morning.Not that the controlled environment didn’t provide some physical challenges: there was the chlorine.”You should see me, I look like Zorro.” Garbarino wore only a bathing suit, bathing cap and goggles for the challenge and used petroleum jelly to prevent chafing. But he said the skin under his arms is burnt away from chlorine and chafing.The most salient challenge was, however, the time.”If people didn’t come in at middle of the night, if friends hadn’t come in, I don’t know if I could have done it,” Garbarino said.But friends and family members cheered Garbarino from the stands throughout the day. Friends and regular Y swimmers got some laps in and/or chatted with Garbarino or just got some inspiration. Simione fed her husband fruit and nut bars, “gel goo,” water and even tea when he got cold.”I told him he’s going to start talking like a dolphin,” Tricia Garbarino-Titus, Garbarino’s sister, said, as the final hour clicked away.Garbarino said after the race that he did feel like he “became part of the pool.” And he wouldn’t divulge details of his next challenge, saying his next swimming goal involved avoiding the pool for a week to recover.”After all, I jus