I installed an airhead composting toilet in small trimaran
I owned. It was expensive, but I thought the savings in weight and space was worth it. Instead of using their urine collection bottle, I used a 3-gallon holding tank
which filled by gravity and could be hand pumped out when and where appropriate. This worked very well.
I used the toilet and boat on a 6-day cruise
in SE Florida
and then seven week long cruise
to the Bahamas
. All in all, I was fairly pleased. I experienced less odor
than most boats equipped with holding tanks
. The little electricity needed to power the small exhaust
fan was hardly noticable, even on an outboard
driven boat producing little power.
After the 6-day cruise, I simply let it continue to composte without turning until spring arrived. At that time, the contents were dirt and there was no odor
and not even any toilet paper visible. On the longer cruise, I had to empty it twice. Being able to hold for 2-3 weeks with only a few pounds of weight and five gallons of space was a vast improvement over even most large holding tanks
. This time frame allows one many options to find a place to legally dump. If one hasn't let it sit, all the contents will not be composted, but much will, so one is dumping a lot less raw sewage than with a traditional holding tank system. Ideally, it would be nice to let it compost a few days after the last use, but his isn't possible on a long-term cruising boat with only one head. The composting kept up fine with two people using it, but I question if it would be able to keep up with four or more using it on a regular basis.
The only maintenance
issue I had with the unit was the fan. A small amount of water
coming in through the vent can short it out, so I recommend you carry a few spares.
Personally, I think the airhead composting toilet is a great choice for pocket cruisers on short trips or someone keeping a boat near their home on an inland lake, where one can swap out the lower units and let them continue to compost off the boat. However, for larger boats, where the weight and space of a holding tank is less of an issue, I'd stick with a conventional marine head
. Personally, I like the convenience of the gravity feed tanks that can be easily emptied where legal
and appropriate with the simple turn of a valve.