That's what I'd do on a small boat
No plumbing except a vent and pumpout hose...no maintenance...and the 5-6 gal model holds as many flushes as a 15-18 gal. tank connected to a marine toilet.Btw, portapotty mfrs add the designation "MSD" to their model names and numbers to show that it's a version intended to be permanently installed and fitted for pumpout instead of a portable version...but "MSD" doesn't only apply to portapotties. Federal law defines an MSD as "any equipment for installation on board a vessel which is designed to receive, retain, treat, or discharge sewage, and any process to treat such sewage." So ALL toilets, tanks and treatment devices--including both portable AND permanently installed portapotties--are MSDs. So when searching portapotties, you don't want to search for "MSD"...that'll bring up every type of marine sanition device on the planet...make your search term specific to the type of MSD--manual marine toilets, electric marine toilets, holding tanks, portapotties etc.Thetford and SeaLand Technology are the brands you want to search for either type of portapotty.