toilet dumping into grey wate tank

[VinceU]

Originally Posted by Sobeit

I have a 2003 Sunseeker. During the last camping trip, the black water began backing up into the toilet because the tank was full (of course the guage only indicated 2/3 full). Before I could go outside and open the valve to drain into the park's sewage system, I ran some water into the bathroom sink. The sink backed up and wouldn't drain until I emptied the black water tank. The grey water and galley tanks were not full when the black water backed up (They may each have been 1/4 full).

Does this indicate that the bathroom sink empties into the black water tank? If so, since the kitchen sink empties into the galley tank, the shower must be the only water draining into the grey water tank. I am totally confused...

I once a1998 Gulf Stream 22'C. Same thing, head and Lav to black and kitchen/shower to Grey. Allows more time on grey tank filling. Mfgr's option due layout of tanks and drains?