I installed a C-head earlier this year in a boat I restored.
It is clean. It doesn't smell (unless...I'll get to that in a minute). It is simple. It is cost effective. It uses no electricity (unless you want to vent it and I don't...and you can vent it by using the Venturi effect at the vent pipe outlet rather than a fan). It requires no through hulls so it improves safety
I started using it during the later part of the boat's restoration
. That was in March. I didn't empty the solids until the bucket filled up because I wanted to do a smell test with it unvented. I emptied it last week. It never smelled even in the hot north Florida weather
other than a slight musty odor
when the lid was lifted...which was not unpleasant.
As a test I didn't empty the gallon pee bottle with it sitting in the head
in the closed boat less than half full for two weeks. It stunk up the whole boat. I emptied it and sprayed the bottle with KaBoom and washed it out with water
and put it back in the head
. The smell was gone (if I had left it longer the smell may have permeated things but it didn't in this case).
As a result of my tests and visiting service
station bathrooms for half a century I am convinced that the distasteful smell is overwhelmingly due to the urine rather than the number 2. Separate it and empty the bottle frequently and you have a smell-free system. That's what C-head is. It's not recommended that you leave the pee bottle sitting in the head partially filled for long periods. Empty it as often as you can.
As far as the bugs go...you put a cup or so of diatomaceous earth (available in big box store garden shops) in the head with the peat moss and any insect larvae are killed (not a pesticide...it is a fine natural crystal with really sharp edges that cut the larvae and cause them to die). This trick is included in the recommendations from the vendor. Who...by the way...gives GREAT customer service
I like the C-head so well I am going to pull the head and holding tank/piping/three way valve/macerator (all new and unused) out of my other boat and install a C-head in it. In the holding tank
location I can add another 200+ ampere hours of house battery
. I can glass over the pump-out connection hole and the sea connection for flushing water
and the at sea discharge connection (which is in a locker in the head and the hose and sea valve take about half the locker volume. This locker is where the compost and diatomaceous earth will be stowed).
Oh BTW. Embarrassingly I spilled a bit of the contents of the composting bucket on the deck
when I was emptying it into a garbage bag. Here is the photo
of the result...
It was dirt...nothing but dirt...with NO smell. Maybe I got lucky. But it was just dirt.