Robbin, There was a thread on this delicate subject back I think in December, and based on what I learned then, and following Doug Kelch's lead, I have bought (for the same cruise) a Pett dry toilet system, which seems to have a lot of advantages over the standard porta-potti. If you are thinking of replacing your built-in, you may want to consider it. Lots of information online on the system, which uses zipper bags pre-filled with chemicals which process the material into a semi-solid form which can legally be dumped into any trash bin. No flushing, no tank to dump, and no necessity to scout for dumping facilities. I found also that when the legs are removed it fits solidly into the starboard v-berth storage hatch opening. It's not flush with the surround, but can easily be closed and stored when not in use. Full disclosure - I haven't used it yet, but plan to test it out (informally, of course) sometime before the cruise. Rick Davies M-17 Lynne L #633 PS It's also cheaper than a porta-potti. ************** Wondering what's for Dinner Tonight? Get new twists on family favorites at AOL Food. (http://food.aol.com/dinner-tonight?NCID=aolfod00030000000001)