I agree with Dan...
The VacuFlush is a very good toilet, but overpriced. Once upon a time it was the only game in town if you wanted to flush with fresh water and use less than 2-3 gallons/flush...but that's not true any more...every major toilet mfr now offers at least one (some offer several) toilets than can use pressurized flush water, use .5 gal or less (which is actually about the same amount the V/Flush needs despite a very carefully worded claim that it can use "as little as" one pint) for as little as half the price of a VacuFlush.All toilets designed to use pressurized flush water are VERY quiet--quieter even than most household toilets...'cuz contrary to what most people think, it's not the discharge pump and macerator that make all the noise, it's the raw water intake pump. So IMO the pressurized flush water version of the Raritan SeaEra, for around $400 would be an excellent choice for your boat...only draws about 10a/flush and uses about .5 gal/flush. You can check out all the specs here: http://www.raritaneng.com/products/toilets/electric/sea_era.html