Whale - Gulper Grouper Mk3 - Fishbox / Waste Pump with 90 Degree Ports - 24V - BP4774. Non clog electric Waste pumps without filters, built on more than a decade of market leading valve technology.. Proven Diaphragm Technology:. Whale Gulper waste products have been at the forefront of marketing leading waste technology for over 2 decades. Rather than impeller motors, Gulper pumps contain reciprocating heavy duty diaphragms and specialized non-choke valves to handle grey, bilge, black and fishbox waste on board.. Ideal Macerator Replacement in Fishbox Installations:. The Gulper Grouper Mk 3 builds on the decades of proven pump technology and now features 90 inlet and outlet ports with integrated non-choke valves. The improved design allows the pump to be used as a direct replacementfor macerator impeller pumps. Compared to typical macerators, the Gulper Grouper Mk 3 is quieter and lightweight. With diaphragm technology, the pump does not clog or suffer from motor burn out meaning a lon