Four children sat in a boat on their school’s gym floor Thursday as Department of Natural Resources officers shook it and a crowd of their classmates loudly counted down. The kids tried to buckle life jackets, practicing water safety at one of five safety stations set up at Gainesville Exploration Academy. After 15 seconds, most had their life jacket part of the way on, and Sgt. Mike Burgamy with the Department of Natural Resources pointed out what might happen in a real-life situation on the lake.