Cheap submersible livewell pumps hanging over the boat or in a full live well will supply low pressure water. To aid in washing and clean up. The wash down pumps or RV 12 volt water pump with and on off nozzle on the
end of your hose will give you more pressure for spray down and such. We use one plugged In To cigarette lighter socket on the back of houseboat. The pumps stays off until you start spraying with nozzle open, it works great for washing fillets and clean up of fillet station on the boat as well as washing the decks,