Hi… Can't believe this is the topic that I'm jumping in on for a first hello, but it's the one I know the most about… I have a Bolger Chebacco (that will hopefully have a junk rig starting in the northern spring of 2014) and it has a homemade version of a separating composting head. I lived aboard the boat for seven months in 2012, and for four months in 2013, and the system worked out well.

I'm sorry to say that I do use peat moss, but that's because I have serious respiratory reactions to about a million different things, sadly including coir, and sawdust, and wood shavings. Coir would be fantastic, if not for that issue.

On the subject of smells and composting heads, it really does make a big difference to separate the liquids and solids. In the humanure book they talk about not doing that separating, but the reason that it works is because on land you can use loads of cellulose-type material in each bucket, because you have loads of space in the outdoor pile. Urine has lots of nitrogen, and if that nitrogen has lots of cellulose to work on (I think it bonds with the carbon – it's been a while since I read the book), there's no problem – but if the nitrogen gets to sit with other nitrogen, the nitrogens bond and become ammonia – hence the smell. Poop on the other hand is not high in nitrogen, so does surprisingly well with a very moderate amount of cellulose-type material to cover it.

I did a blog this year, sailing, and there's an entry devoted to the homemade version of an airhead. I did spend about $100 on a dividing plastic toilet bowl made for composting outhouses, the "privy kit" http://www.ecovita.net/privy.html but otherwise the materials are pretty basic. If anybody is interested, you can see the post here: http://sailingauklet.com/2013/09/22/homemade-composting-head/

I haven't yet tried putting sugar in the urine container, because I dump it each day and the container is a 1 gallon plastic jug like for bottled water or milk, and it's easy to change it out when it gets nasty. They last a good while if they are rinsed when emptied. I did however add a holding tank to the boat, for liquids, for in case of being somewhere for longer than two or three days that really wasn't appropriate for dumping pee over the side. Cuttyhunk inner harbor, and the Great Salt Pond at Block Island, Rhode Island, USA are places like that. But as it happened, this year I never stayed someplace like that for long enough to need the tank. That's nice, because it's still brand-new clean… But I was planning to sail to Canada, where they say that a holding tank is a requirement, so at least the boat is something like legal. Anyway, on the sugar, I think it would be really good in the "liquids only" holding tank. Maybe it works because sugar has so much carbon, and that bonds with the nitrogen? It's so simple, compared to commercial head treatments…

Anyway, thanks for the great website – what a tremendous, and broad, collection of information.

Best regards,

Shemaya Laurel