Now that we've gone with a composting toilet, we need something to take care of the ... um ... poop. The magic ingredient that helps convert the waste to dirt is Peat Moss, aka Sphagnum.
Peat Moss serves to desiccate, or dry up, all the moisture in the stuff. Once all of the liquids are absorbed, what you have is dried out stuff that isn't smelly and has the consistency of dirt.
Since buying our first block of peat moss, we've learned that we can also use coconut fibers. Given where we will be sailing, getting coconut fibers may be a better alternative.
Coconut husks need not fear immediately however. From studying composting toilets and using Peat Moss, we understand that our 1 cubic foot of it will last us between 6 months to 1 year.