A boat is a constant work in progress, and this summer, it was time to re-do the heads of our sailboat. After 20 years, both our marine toilets had experienced enough. The motor of our electrical toilet stopped working while our manual toilet smelled bad no matter what we did. The fix for the electrical toilet was easy. A new motor and some awkward cleaning later, it was running like new, but our manual toilet needed a more significant adjustment. It was time to convert our marine toilet into a composting toilet for boats.

Table Of Contents

• Marine Toilet Options

• What is a Composting Toilet?

• How to use it?

• Boat Review

• Conclusion

Marine Toilet Options

There are 3 main possibilities for discharging human waste on a sailboat. Number one is the ceramic marine toilet which uses seawater to flush it all out to sea. This “feed-the-fishes” option can be used at sea. To use the ceramic toilet in marinas or at anchor, you need to pair it with a holding tank. As the names suggest, a holding tank holds your creations until you find a pump-out station to discharge them.

The third and newest option is composting toilets. These are not port-a-potties or chemical toilets but waterless systems that use decomposition and evaporation to recycle human waste.

How does a marine composting toilet work?

The idea of a marine composting toilet is straightforward. It’s a physical toilet that creates an oxygen-rich environment, enabling aerobic bacteria to convert solid waste into compost. In less scientific terms, the toilet does not use water to dispose of human waste but collects it and transforms it into soil. The system stays odourless due to a fan system and a naturally sourced medium such as coconut coir or peat moss used to line the tank. Moreover, a urine-­diversion dry composting toilet (UDDC) like Air Head speed up ­decomposition due to the separation of liquid and solid waste.

How to use a marine composting toilet?

I have to admit the first time was pretty weird. Between being scared to miss and trying to relax to do my business, it took longer than usual. After a few times, it feels normal, though. 

To use the compost toilet, open the trap door BEFORE doing your business. Then you place your beautiful bottom on the toilet seat, which by the way, is the same shape and size as our ceramic toilet, and do your business. Once the business is concluded, you close the trap door and toilet seat and stir the pot. Simple as that. To keep the composting toilet tidy, we usually wipe it down after use and spray diluted vinegar every few days.

Composting toilet for boats - Review

We chose a composting toilet for our boat mainly because of its eco-sustainability and easy installation. We keep it because it is odourless, easy to use, maintenance free and regulation compliant. 

• Eco-sustainability 

Air Head composting toilet does not use any chemicals or ulterior systems. Compared to a holding tank that uses chemicals to keep the waste stable and pump-out stations, it’s a no-brainer decision regarding eco-sustainability.

• Easy Installation

No water means no seacocks, sanitation hoses, or seawater pumps. Once you know where to place your vent, a few screws and stainless-steel brackets install the rest of the system.

• Odourless

Not one whiff so far. Neither the liquid nor the solid waste has given us any trouble. We lined the solid tank with a naturally sourced medium provided by Air Head which controls the moisture and makes it more appealing to the eye when you open the solid tank to do your business.

• Easy to Use

While flushing is more comfortable than stirring the pot, the composting toilet is easy to use. The only downfall is the toilet’s height, which calls for a step on our sailboat.

• Maintenance free

No sea water pump to service, sanitation hoses to change or seacocks to maintain. Besides the little vent, there is nothing that might need your attention.

• Regulation Compliant

Best of all, this toilet will allow you to travel worldwide. The Air Head is considered a Type III Marine Sanitation Device equivalent to the international IMO MARPOL 73/78 regulations.'

Conclusion

Overall, we found no negative aspects to our Air Head composting toilet after one month of use. So far, we emptied the fluid tank twice while sailing off-shore without problems, but never the solid tank. We will update this blog post and publish a YouTube video once we do. Subscribe to our newsletter to get notified when we complete our Air Head composting toilet review.