Chuck Kanter has over 20 years experience as a yacht surveyor specializing in multihull vessels, sailing vessels and small craft. He is a recognized authority and featured speaker on cruising in catamaran sailboats. The KISS system allows you to install or retrofit the best possible working system without complicated plumbing, electrical connections and drilling a minimum number of holes in the boat. The concept The concept is simplicity itself. The tank, installed above the waterline, is emptied overboard by gravity.
All waste goes through the tank.
The toilet pumps directly to the top of the tank. The toilet itself can be either manual or electric, it makes no difference. One of the fittings goes to the seacock, the other to the deck pump-out fitting. To use the tank, you close the seacock. To flush straight through, you open the seacock.