Not huge fan of porta potties. In preparation for our build, I have accumulated:

I use a £21 luggable loo

What a shame.  But maybe the people who look after the landscaping around the marina might be interested in your compost?

Neil Tanner wrote:Update on the five gallon plastic 'ThunderBox'....after five days of use on Sea Elf with outside temps around 85 deg. F., not separating liquids from solids and using the white pine shavings, I am happy to report no odor noticed down below.  The lid is sitting loosely on top and the only time I notice a 'smell' is when I take the lid off to use it, but it isn't bad.  We have slip renters here that have holding tanks that have gone 'septic'.  All I have to do is walk past their boat and it knocks your socks off.  The bucket and shavings may look third world but it sure makes sense to me!

If you put the gold you are creating into a compost box with some grass clippings or seaweed you'll be producing some of the best compost for garden or trees that you can find.

An update to this post. Composting removes the waste component of our body's products and completes the nutrient cycle placing the minerals and other excesses from our bodies back into the growth cycle of plants. Good for us, good for water and good for the earth.

Having used the pail in a box "Lovable Loo" advocated in the Humanure Book for some ten months now here are a few observations. The system works! We use peat moss as our absorption material as we have not  found a supply of the type of sawdust we need. With two people we need to empty the pail,3.8 gallons, about every two days. Built a compost box four x four x four feet and filled the bottom foot with eel grass. We use grass cuttings or eel grass to cover up the contribution which is dug into the centre of the compost bin. It really heats up. We put all our compostables in from the galley along with any fish parts that we get after taking off the fillets. No smells,minimal maintenance and we just feel better about making topsoil instead of waste. Our water consumption on land is about the same as when we are at sea.

I don't think I would use this system at sea as the storage of peat moss and subsequently the compost (until we reach land) is not practical. When we start off in October for a long cruise we'll continue to use our pumpable Thetford marine toilet on Easy Go.