There is one thing that everyone on a boat likes to discuss and that is toilets.

For those of you not on a boat I’ll give you a quick overview of the different types available with the Pros & Cons of each. But, basically you have to sort one method or another of getting everything that comes out of you off your boat !

Common Misconceptions

The first thing to clear up is that the contents of your toilet should NEVER end up in the canal. Some people assume because your grey water (water from washing up, showers etc) goes straight in to the canal then your toilet waste does as well. It doesn’t. I know for sea going boats it’s different but on the inland waterways it is a definite No-NO.

Pump Out Toilet

This does what it says on the tin. When you flush your toilet it goes in to a holding tank on your boat. Quite often this is under your bed…… Then, when this becomes full you need to arrange to get it pumped out of your boat. How often you do this will depend on how many people are on your boat and how big your holding tank is but on average about once every 2-4 weeks.


  1. This is the most like a conventional toilet and, in theory, doesn’t need you to “do” much to it.


  1. You have to pay for each pump out. This is somewhere between £8 and £16 per pump out.
  2. You need to plan for each pump out when you are cruising.
  3. You lose a chunk of storage space for the tank
  4. Blockages – need I stay more……

Cassette Toilet

If you have ever been caravanning the chances are you have used a cassette toilet. A toilet bowl sits over a smaller cassette tank. The tank is removed for emptying. On average 2 people may fill a cassette in 2-3 days.


  1. Easier to replace if it goes wrong
  2. Easier to find an Elsan point on the canals to empty it


  1. Needs more frequent emptying so you will need spare cassettes.
  2. The smell. Especially when emptying. It doesn’t seem to matter what chemicals you use in it they still stink.
  3. A full cassette is heavy ! You’ll need to lift them in and out of the boat….

Incinerating Toilet

Yes, it really does burn your poo ! These can either run on gas or electricity and all you are left with is ash to empty…..


  1. Doesn’t need emptying very often
  2. Easy to empty


  1. VERY power hungry. The electric versions use about 1.8kW on a 230V supply.
  2. Expensive to buy (Upwards of £2,000)
  3. Expensive to run (costs of gas or electricity)

Composting Toilets

These are quite often called composting toilets but the composting process doesn’t happen within the toilet so they should really be called “waterless” or separating toilets.

The way they work is that your liquids and solids are separated in to two different containers (a bucket for solids and a bottle for liquids). You don’t need to add any chemicals and they do not smell.

The liquids bottle can easily be emptied down any toilet or (according to the environment agency) it can be poured on to the ground to soak away so long as it is 10m away from a watercourse and less than 10 litres per day (an individual will produce far less than this !!). So, it really isn’t difficult.

The solids, in an ideal world, should then be used for composting and several books have been written about this. The practicalities of living on a boat mean that this is not normally possible for most people so the CRT ask that people double bag the waste and put it in the rubbish bins (ideally in compostable bags.

I know the immediate reaction is Eeww but it is far less offensive than a week old chicken carcass and, unless someone has a medical condition, no more harmful than most things that get put in your kitchen bin and doesn’t contain the plastics etc that nappies do.


  1. No smell
  2. Easy to empty
  3. Not reliant on finding an Elsan or Pumpout point
  4. No water usage
  5. Very low on-going costs


  1. The initial embarrassment of being seen carrying bottles of pee
  2. You may need to store the bagged solids waste until you find a bin. (Don’t worry, it doesn’t smell !!)

We have chosen to go down the composting toilet route and it really is the best thing we have ever done. We have a vac-flush cassette toilet on the boat when we bought it and that really was the worst of both worlds. It was noisy, smelt and we had to change the cassettes on a daily basis (with two of us using it).

It took us five hours to get the old toilet out and 15 mins to install the new one.

I made a short video to show my sister how it works, I’ve included it here so you can see a bit more about it. We bought it from Compoost.

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