This puts them at risk in three areas, he said. First, these showers are used at the stern near the area where engine exhaust is being emitted. So CO poisoning is a high threat. Second, they could be scalded by the hot water from the engine. Third, since the engine is running, there’s a chance that the engine could be shifted into forward and the person could fall overboard and be injured by the propeller.
The Coast Guard understands that many ski boats have been modified to incorporate this type of hand-held shower installation.