Mayfair Replacement Automatic Bilge Pump by Johnson Pump The Johnson Pump Automatic Bilge Pump is designed to directly wire in to your crafts electrical system with ease. Automatic bilge pumps are particularly useful by operating with a sensor that self regulates the exiting of bilge water and this pump is available in 500, 750, or 1000 gallons per hour GPH. The upkeep of this gadget is important when considering that too much water can affect a boats maneuverability. This pump offers a manual t