A more important question...
Will it fit in your head? The tank has a footprint of about 19" x 20" and it has to sit level. Making it level can be solved by making a platform for it to sit on, but not only must there be room for the tank, there has to be room for the person using the toilet...and, if the head door opens inward, room for it. If it will fit, IMO it makes no sense at all to install an electric water pump just for the toilet, since the same pump can replace the manual water pump for the whole fresh water system. People who don't have enough fresh water to spare any for the toilet have installed raw water intake pumps plumbed to a thru-hull and wired them so that stepping on the pedal turns on the pump, but that defeats the whole idea of using fresh water to eliminate sea water odor, plus it increases the amount of flush water, filling up the tank a lot faster. So even if it will fit, unless you're willing to convert your entire fresh water system to pressurized water, I think you'd be better off with a different system.
