TimC

Yes. Basically, what you have is a single tank divided vertically up the middle. The division does not go right up to the top. The part of the tank on the centre line tank fills up first, then once the contents reaches the top of the division (effectively a baffle plate) it can then start filling up the side part. When you pump out, you are pumping out from the bottom. If you only use one of the pump-out sockets, you will only empty the part that that is connected to. Hope this makes sense.

Hi - I am assuming that we are talking one toilet? From what you say, sounds like this is a 57' with the convertible single/double beds at the stern, then bathroom then double bed. In which case, there is ONE tank under the double, but it is spilt in two. The central section fills up first, thus not affecting the list of the boat, then it will start overflowing into the side tank, at which point the boat starts to lean over! There are two emptying points, but it is one big tank. Timed pump out tend not to allow long enough to empty the whole thing out. Some places will try and charge you for two tanks.

Hi - Just found this thread! We have former Black Prince Boat Dawn, now Sola Gratia. Continuously cruising, currently on the Llangollen at the time of posting.