So, I diverted a bit from normal practice here and had long ago decided to use a composting head instead of a ‘normal’ marine head – you may remember me pulling out all the head plumbing and holding tank. A normal marine head has two thru-hulls, one for intake of sea water and the other is the ‘outlet’ pipe, where you can discharge the holding tank – you can’t do this legally within 3 miles of the coast however. The usual way it works is that all the pee and poo and stuff goes into a ‘holding tank’ which is a tank/bag full of gross stuff. Then you get this sucked out every so often or motor 3 miles offshore and discharge it.
These are great when they work, however
– you have two below-waterline thru hulls, which if a hose slips or splits, leads to a lot of water coming in, real fast, and you are going to have a Bad Time
– they tend to smell, REAL BAD, after a while. Unless you replace the hoses every 6 months to a year and that’s a terrible job
– the holding tank sometimes leaks, or a hose spilts and then you have raw sewage sloshing around in your boat
– they are kinda confusing to use (the manual kind anyway, there are electric ones now that are basically Push Button)
– have to pay for a pumpout and thats another gross job
I basically went for a composting toilet for all those reasons http://natureshead.net/
They do have disadvantages compared to a traditional head though
– pee bottle needs to be emptied every few days
– they don’t really like heavy usage (say a crew of 4-5 using it full time on a crossing)
– if the solids and liquids get mixed up, you are gonna have a Bad Time
– it’s a bit different from a standard toilet and some people might get creeped out by that.
Having made my choice, the first thing to do was look at the space left behind by the old head.
The natures head needs a vent hose – I decided to run it straight into the old pumpout station
Finally, I just had to screw the toilet in place, and run wires from the control panel to the toilet, to power the tiny PC fan that pushes air around. As installs go, it was pretty easy!
The last thing I have to do is replace the pumpout hole with a proper mushroom vent with screens and that can be sealed, but for now I’ve just put a mesh over the hole.
We will see how the head holds up!