Yeah, I have one of those on my boat and they do work fine but you definitely can not wait 27 craploads to empty it out. Those "27 flushes" is how much the clean water tank can hold, not an indication of the waste tank capacity which is nowhere near 27 jobs. It's more of a daily thing - every time you dock if it's been used you gotta lug it down to the clubhouse, and emptying it is no fun either. For landlubbers a composting unit that separates solids and liquids would be way better for anything that you don't want to empty on an almost daily basis.