I saw a guy on the river a looong time ago tie up a new 13' Boston Whaler under his pumpout through hull. (This was before dumping waste into inland waters was so punishable and regulated--1970's) Anyway, he turned on the pump and blue holding tank sludge filled the little boat up to the brim. Good thing it was a whaler or it would have sunk. Honest to goodness funny stuff...
