Originally Posted by Cruisingdad
1-3 gallons pp/per day, with 2 being a fair average depending on the head and the water/beer consumption. You can get one by dry bowling and conservation flushes, and three after Mexican Food night.
There is a rule amongst cruisers:
If its yellow, let it mellow. If its brown, flush it down.
Since that makes for a stinky boat we have a different rule. If you are a boy and aren't in a marina then you pee over the side (legal, even though bucket and chuck it is not).
A 20 gallon tank lasts 5-7 days of cruising for us, a sample size of one couple.