We were on a mooring ball (51' sloop) early one morning, years ago, at Cooper. One of the newbies got up and decided to start the engine to charge the batteries. It started and he slipped it into forward. The boat jump forward and started going in circles with the bow tied to the mooring ball pennant. By the time we shut it down, we had made "several 360's". There was a man standing in the cockpit of his sail boat next to us who said in a deep British accent: "You're going in circles!"