Rebuilding the head system and have a concept want to run up the flag pole. Looking at the outlet of the holding tank and going to a deck pump out and a pump out when out to sea. Here is my idea, go from tank to Y valve, one side goes to deck pump out other side goes to another Y valve. From this Y goes to a waste pump, up to a siphon break and down to the through hull. The other side of this Y valve is the emergancy/back up bilge hose. The thought here is that I can double role the large pump, holding tank pump out when outside limit, and backup bilge pump the rest of the time. As well this would allow me to flush out pump, siphon break and hoses when I do use them to pump out holding tank. Whats your thought? Thanks Burry