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There have been several requests for more info on why we decided to revert to a traditional marine head from the composting toilet that we installed earlier this year. So, to give our readers the “down and dirty” truth that they seem to want, here goes…

To start, a key requirement seems to be that the head be vented properly. This venting is not only to remove smells but also to aide the composting action of the toilet. I chose to use the supplied computer muffin fan and vent the toilet through the old holding tank vent hole on the inside of our starboard hull about 2.5 feet above the waterline. When I had posted this before, I read some comments that felt that this would be inadequate. The same poster wrote that a 4″ hole would be required. When I discussed my plan with the retailer, I was told that no such large hole was required. He said that only a small hole was needed and he thought that my plan would work. Why did I choose to go this route? I simply didn’t want to drill any more holes in the boat!

For composting medium we chose to use coconut coir. This was purchased from Home Depot before we left Canada and was fairly inexpensive. When added to water it expands in size a huge amount. We bought two packages of it for about 30 bucks and I bet we would have had enough for a couple of years! We also purchased some enzymes from Sun-Mar which, when added to the composting medium, apparently contribute to the composting action. This stuff also contains citronella which the label says helps to repel insects.

So, the big thing everyone wants to know is “does it smell?” Once the composting action begins I would say no, there is not really any smell of waste. There is however an “earthy” smell and when the enzymes are added, a strong smell of citronella. When I contacted the dealer shortly after getting the unit to ask about this, he said “it will never smell like a rose garden” but it shouldn’t stink. I would say this is accurate I guess.

With all that said, here is what we didn’t like about it:

1. The head (bathroom) was always dirty because little bits of the coconut coir would get spilled. This required a lot of extra clean up.

2. Dumping the urine every two days was not a huge deal but it is still a hassle that is not required with a holding tank head.

3. It is big, and high! Our boat is not large and it barely fit. It was so tight in fact that we couldn’t use the supplied handle to stir it. We actually came up with a method of using a ratchet and socket to stir the head. Because it is so high and our head, like many others, has a small platform that the previously installed compact head sat on, we needed to use a step stool to comfortably access the Nature’s Head unit.

4. The biggie… Insects. On two separate occasions we had an infestation of insects so bad that we had to completely dump and clean the unit. Dumping is one thing… cleaning is an entirely worse procedure!

About four or five days ago I noticed that the muffin fan wasn’t on. The plug which supplied the power to the fan was never really secure. If the wire was jiggled a bit it would stop, or start. Remember that this venting is required? Obviously this wasn’t good. When I noticed that the fan wasn’t running and looked down to jiggle the wire, hoping to restart it, I noticed that the vent hose was full of water! Yes, water, almost to the level of the head. The previous days of hard sailing in big waves had allowed water into the vent hose. Obviously no venting had been going on! This is strange because we noticed no difference in smell. After draining the water and still not being able to get the fan to work, I took it apart. My troubleshooting determined that the fan was toast, perhaps caused by water ingress or overwork. Oh, and there were a bunch of flies in the toilet!!! This was the straw that broke the camel’s back and a decision was made by the two of us to replace the unit with another Jabsco.

Fortunately the holding tank and discharge hoses were all still installed. I never removed them when I installed the composter, wanting to ensure that we had a fall-back plan.

The final interesting part, which makes me believe that we never had it vented properly in the first place, is that it took us several days to acquire and install the new head. During that time we continued to use it, without it being vented (what choice did we have) and there was no increase in smell.

I know there are some people successfully using toilets like this on boats so if you choose to go this route, your results may be better than ours. In fact, I hope they are.


  1. I recall you added a strainer on the inlet to your old Jabsco, to keep out weeds. I’ve had that problem twice in Chincoteague (requiring taking the pump apart to clear) and I’m in the process of adding a strainer. How did it work out? Did it help?

  2. Mike — Good information. I love the down and “dirty” ones that talk about the issues you have maintaining your boat.

  3. I’m sorry to hear the composting toilet did not work out for you. We installed an Airhead toilet on our boat and so far we are pretty happy with it, though we aren’t living aboard yet and the longest we’ve stayed aboard at a time so far is one week so our experience is pretty limited compared to yours. I admit that I don’t love dumping the urine jug but for me it is better than visiting a pumpout station! I’m curious about the COIR getting loose in the head, was this on a daily basis or only when you were starting a fresh batch? We installed a 4″ Nicro day/nite solar vent (yes it was painful drilling that big hole in the deck!) instead of the stock fan, I can’t imagine a holding tank vent hose would be able to move enough air to adequately vent the unit and I’m surprised the retailer thought this would work (though that doesn’t seem to be the source of your toilet woes). Regarding insects: we did get some gnats, apparently fungus gnats love compost if it isn’t kept moist enough. I added extra water and sprayed some insecticide into the bowl and haven’t had problems since. I really hate using insecticide so when it is time to dump the solids I plan to add a little diatomaceous earth to the next batch of COIR. Anyhow I am glad you still had your holding tank in place going back to the Jabsco wasn’t too difficult or expensive.

    One final thought for any of your readers debating the Airhead vs. Nature’s Head: one reason we chose the Airhead over the Nature’s Head is that emptying the Nature’s Head urine jug requires tipping the seat back and exposing the solids bin whereas with the Airhead the urine jug can be removed without lifting the seat. Hm, have I exceeded the allowable comment length yet?

    • Good tips for those considering this route. When I say the coir was messy I meant that we would spill little bits during the process of adding some to the head. You might be neater or more accurate than we are. 🙂

  4. I’m really glad to have an AirHead on the way… still. Your initial post WAS disconcerting but now this ‘down and dirty’ one clears it up very nicely. We have a 4 inch hole already and our measurements might be less constraining as well. All in all, and thanks to the great tips from Rowan, I feel very confident we will succeed with this unit… with some patience of course. We’ll be sure to update anyone that is interested on our blog (no plug intended). Thank you all.

    • As I said at the beginning, I blame at least a portion of our issues on my chosen method of install, and our particular boat. Fortunately it doesn’t sound like you’ll have any of those issues.

  5. […] took it out or what they didnt like about it? Their reasons are posted on their blog, here: More pottie talk | Zero to Cruising! I was not trying to say whether this was right or wrong, only that it might be reasonable to leave […]

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