TAHOE CITY, Calif. and#8212; Regional emergency crews on Tuesday rescued a man who had been floating for nearly two hours in Lake Tahoe after his friend dropped him off in the water to swim and eventually lost sight of him, an official said.Two men in their early 20s rented a personal watercraft from a local business and took it out for a joyride Tuesday afternoon on the lake, heading from Tahoe City toward Emerald Bay, said Placer County Sheriffand#8217;s Office Sgt. John Giovannini.One of the men allowed the other to swim in the lake while he continued to ride around; …