A big shout out to the list. The advice is universally disconnect the overboard discharge of black water. I went the list one better and removed the entire overboard discharge system, macerator and all, plugged the thru hulls and replace the remaining sanitation hose with new. It has been nine years since I needed to use the overboard discharge. Every year at recommissioning, the macerator pump needs some sort of service, usually sticking a screwdriver into the slotted shaft at the end of the housing and giving it a turn to free it up. Needless to say, that end of the macerator is inaccessible. Since the two of us can go two weeks between pumpouts and working pumpout stations are much more frequent, we decided to do without the frustration of one more Jabsco pump. And, when the authorities want to see the disconnected hose, I will show them the hose, macerator, and Y-valve. Yuck. Bob Salmons Veronica Willard 40 RPH