Abstract: An apparatus for rinsing the interior of a marine engine that is attached to a boat immediately after the boat has been removed from a body of water. The apparatus is adapted to be affixed to the frame of a boat trailer in order to be carried by the boat trailer. A first reservoir holds as much fresh water as seems necessary for the cleaning job to be faced. An air tank holds compressed air and is placed in communication with the water reservoir at selected times in order to create a portable source of pressurized water. Appropriate hoses, wands, adaptors, cups, nozzles, etc., are provided for directing pressurized water that is released from the water reservoir so that the water may accomplish a flushing/rinsing job on a boat and engine and any accessories immediately after they have been removed from a lake, etc., while the engine is still hot and before any salty or foul water evaporates inside the engine.