The blue lights started flashing as Deputy Drew Long took a sharp U-turn with the Forsyth County Sheriff’s Office boat in the open water of Lake Lanier. Moments before, Long had spotted a moving boat with girls lying on the back, soaking up sun on the opening day of the unofficial boating season. He sped up and steered over the choppy water toward the Cobalt, which slowed and came to as much of a stop as a boat can in the middle of Lanier on a Saturday.