Ah so you are the one that keeps blocking up the bogs when i was on the cruise ships.

A cruise ship bog is actually quite a complex beast as they operate on a vacum principle so there is a kind of relay vavle in the back that opens up the bowl to the vacum and then it dumps in a tiny amount of water only about 1.5 litres.

From there it gets sucked down into a venturi and then put into a small holding tank. this tank has about 4 pumps atached to it all which draw from the tank and then through the venturis and back into the tank. When the tank reachs a critical mass (or full of [censored]) one pump is then diverted to pumping it out into the shittank (sewage treatment unit). In here it get genrally bubbled around and mixed up and oxygenated so the the jobbie eaters (bacteria) can break it down. Then it goes into the cholrination tank where it get chlorinated and then we pump it into a tank to dump at night.

Now any man made system it has problems there is a very course filter before the venturi (granny piss filter) which can find all sorts of strange things in it, towels, faulse teeth, clothes jewlery (yes we can find your ring if you are lucky if you flush it) etc This filter occasionally get blocked. A favorite fault is when the first holding tank overflows or explodes which has happened then vent got blocked and it overpressurised and spilt dumping about 20 tons of sewage into the compartment.

Also we have a vacum pressure metre which monitors the system vacum this tells us if we have a stuck bog which can collapse the vacum and no ones toilet works in a certain area. This metre is attached to a data logger system which tells us many things about the passengers habits.

So respect that cruise ship bog