Limited capacity Holding tank systems Holding tank systems vary in complexity depending on what they are designed to do. There are four basic arrangements. Deck pumpout only. The holding tank is installed in line between the toilet and the deck pumpout fitting. Allows use of existing toilet.
Sewage goes directly into the tank.
Simply to install. Minimal equipment requirements. Does not require a through hull for discharge. External pump required to evacuate tank. Overboard discharge option after the holding tank.