Some surveyors recommend cruising sailors install a clutch-operated bilge pump that runs directly off the boat’s engine. That way, you’ll have a reliable, high-capacity pump that requires no fickle electrical connections. (Large electric pumps can draw 20-30amps, so it’s likely that you’ll need to run the engine anyway.) Xylem makes a range under its Jabsco brand, which runs from 1,470 gpm to 4,100 gpm. They run off a belt and pulley attached to the engine’s crankshaft, just like the alternator, with a manual clutch to engage and disengage. Another option is a standalone gasolinepowered pump, like Honda’s WX10TA, which can shift 1,920 gph through its 1in discharge hose.