Mercury - Quicksilver Sea Water Pump Impeller Cooling System Part Engine-Mounted 2-Piece Pump 59362Q01. Overview. Your MerCruiser's cooling system depends on a steady flow of water, and the Mercury Marine 59362Q01 Quicksilver Sea Water Pump Impeller makes sure that happens. Designed for MerCruiser engines with engine-mounted, two-piece plastic sea water pumps, this impeller is flexible, durable, and built for real-world boating. Its bonded center hub keeps the blades from tearing loose, so water