Best Composting Toilet for Narrowboats
Choosing the best composting toilet for narrowboats can make life aboard simpler, cleaner and far more flexible. Whether you live aboard full time, cruise at weekends or are planning a refit, the right toilet setup affects storage, comfort, odours, water use and how often you need to stop for services.
On a narrowboat, space is limited and every fitting needs to earn its place. A composting toilet can be a good alternative to a cassette or pump-out system, but it is not the perfect choice for everyone. This guide explains what to look for, which features matter most, and how to decide what will work best for your boat.
What is a Composting Toilet on a Narrowboat?
Most toilets sold as composting toilets for boats are actually urine-diverting dry toilets. They separate liquids and solids at the point of use. Urine goes into a removable bottle or tank, while solids drop into a separate container, usually with a cover material such as coconut coir, hemp, sawdust or a similar dry medium.
The aim is to keep the solids dry and well aerated. This reduces smell, slows the build-up of waste volume and makes the contents easier to manage. True composting takes time, so many boaters store the solids in a suitable container after removal if they want the material to break down further.
For narrowboats, the main appeal is independence. There is no cassette to carry to an Elsan point and no pump-out tank taking up a large amount of space. However, there is still waste to deal with, so it is important to be realistic about emptying routines and storage.
Is a Composting Toilet Right for Your Narrowboat?
A composting toilet can be a brilliant fit for some boats, especially where cruising routes do not always pass convenient sanitary stations. It can also be useful during winter, when facilities may be closed or frozen.
It may be a good option if you:
- Want to reduce reliance on pump-out stations or cassette emptying points.
- Have limited water capacity and prefer a dry toilet.
- Are refitting a bathroom and want more freedom over layout.
- Have space to store dry cover material and, if needed, a secondary composting container.
- Are comfortable with regular, hands-on maintenance.
It may be less suitable if you want a completely fuss-free system, have no space for temporary storage, or are not prepared to manage urine bottles frequently. Composting toilets are low water, not low responsibility.
What Makes the Best Composting Toilet for Narrowboats?
The best composting toilet for narrowboats is not always the most expensive model. It is the one that fits your bathroom, suits your cruising pattern and is easy enough to maintain that you will use it correctly every day.
Compact footprint
Narrowboat bathrooms are often tight, particularly on older boats or compact layouts. Measure carefully before buying. Check the width, depth, lid clearance and whether the solids container or urine bottle can be removed easily.
Do not just measure the space where the toilet will sit. Think about how you will stand, turn, clean, lift out containers and access any fan or ventilation pipe. A toilet that technically fits but is awkward to service will quickly become frustrating.
Effective urine separation
Good separation is the heart of a dry toilet system. If urine repeatedly gets into the solids container, odours increase and the material can become wet and unpleasant to empty.
Look for a design with a comfortable seat position and a well-shaped separator. Some models suit different users better than others, so read user guidance before fitting and consider whether guests will understand how to use it properly.
Ventilation and odour control
Many composting toilets use a small 12V fan to draw air from the solids chamber and vent it outside. On a narrowboat, this can make a noticeable difference to odour control.
Before choosing a model, decide where the vent will go. Common options include venting through the cabin side, roof or an existing suitable outlet. The route should be short and practical, with attention paid to weather protection and avoiding water ingress.
Easy emptying
Emptying is where good design really matters. A removable urine bottle should be easy to lift without spilling. The solids container should be straightforward to remove, seal and clean.
If you live aboard, consider how often you are willing to empty liquids. Urine is the part that needs the most regular attention. A larger bottle may reduce emptying frequency but will be heavier to carry when full.
Build quality and cleanability
A boat toilet needs to cope with movement, damp air and daily use. Smooth surfaces, durable hinges, secure latches and simple internal shapes make cleaning easier.
Avoid anything with lots of awkward grooves or inaccessible areas. The easier it is to wipe down, the more pleasant it will be in the long term.
Types of Composting Toilets to Consider
Self-contained separating toilets
These are popular on narrowboats because everything is built into one unit. They usually include a urine bottle, solids chamber, seat, separator and sometimes a fan.
They are often the simplest retrofit choice. You remove the old toilet, prepare the space, install the unit and add ventilation if required. They can work well where there is no room for a separate remote tank.
Compact portable separating toilets
Portable separating toilets can be useful on very small boats, boats without a full bathroom, or as a temporary solution during a refit. They are usually lighter and simpler, with fewer installation requirements.
The trade-off is capacity. Smaller containers mean more frequent emptying, so they may be better for occasional cruising than full-time liveaboard use.
Electric or fan-assisted composting toilets
Fan-assisted models can help keep the solids chamber dry and reduce odour. Some also include stirring mechanisms or agitators to mix solids with cover material.
On a narrowboat, power use is usually modest for a small fan, but it still needs to be considered. If you leave the boat unattended, think about whether the fan needs to stay running and how that fits with your battery and solar setup.
Popular Composting Toilet Brands for Narrowboats
There are several well-known brands often considered by boaters. Availability, price and specifications can change, so always check current details before buying.
- Nature’s Head: A widely recognised self-contained separating toilet with a robust marine following.
- Air Head: Another established option, often chosen for boats and small off-grid spaces.
- Separett Tiny: A compact urine-diverting toilet that can suit small bathrooms, depending on layout.
- Simploo: A UK supplier offering separating toilets and related accessories, often considered by boat owners.
- Trelino: Known for compact dry separating toilets, including portable designs.
The best choice depends on your priorities. Some people value a heavy-duty marine-style build. Others prefer a lightweight unit, a lower price, a particular seat height, or a simple system with no moving parts.
Key Questions Before You Buy
Before ordering a toilet, work through the following points. They can save a lot of hassle during installation and daily use.
- How much space is available? Measure the floor area, wall clearances and removal access.
- Where will the vent go? Plan the route before buying a fan-assisted model.
- Where will urine be emptied? Follow local guidance and use appropriate disposal points.
- Where will solids be stored or processed? Make a realistic plan before the first use.
- Who will use it? Guests and children may need clear instructions.
- Do you need a fixed or portable unit? Full-time living usually benefits from a more substantial setup.
- Can you access spare parts? Check availability of bottles, seals, fans and other consumables.
Installation Tips for Narrowboats
Installing a composting toilet is often simpler than fitting a pump-out system, but it still needs careful thought. A neat installation improves reliability and makes the toilet easier to live with.
Plan the bathroom layout
Mark the footprint on the floor before drilling anything. Sit in the position if possible and check comfort, knee room and door clearance. Remember that some toilets need forward space to remove the urine bottle.
Secure the toilet properly
A narrowboat moves, rocks and vibrates. The toilet should be fixed securely according to the manufacturer’s guidance. A loose toilet is unpleasant and may damage flooring or fittings.
Think carefully about ventilation
If the unit has a fan, keep the vent route as direct as practical. Protect any external vent from rain and canal spray. Use suitable fittings and seal any openings properly to prevent leaks.
Protect the floor
Bathrooms on boats can be damp. Make sure the floor beneath and around the toilet is sealed and easy to clean. A washable mat can be useful, but avoid anything that traps moisture against timber.
Using a Composting Toilet Day to Day
A composting toilet works best when used consistently. The main rules are simple: separate liquids and solids, keep the solids dry, add enough cover material and empty containers before they become too full.
Useful habits include:
- Keep a scoop and dry cover material close to hand.
- Use toilet paper sparingly, or dispose of it separately if recommended by the manufacturer.
- Empty urine bottles regularly and rinse them to reduce build-up.
- Check the fan, vent and seals as part of routine boat maintenance.
- Leave clear instructions for visitors.
Some owners use a small sign inside the bathroom to explain the basics. This can avoid awkward mistakes, especially if guests are used to conventional flush toilets.
Dealing with Liquids and Solids Responsibly
Responsible disposal is essential. Urine and solids must be managed in a way that respects the waterways, other boaters and current local rules.
Urine is usually the most frequent task. Many boaters use suitable toilet disposal facilities where available. Do not empty waste into the canal. If you are unsure what is permitted in a particular location, check with the navigation authority, marina or local council guidance.
Solids from a dry toilet are not instantly garden compost. They need time and correct handling before they can be considered composted. If you intend to compost the material fully, use a safe, contained system and allow adequate time for breakdown. If not, follow the manufacturer’s advice and local waste disposal requirements.
Common Mistakes to Avoid
Composting toilet problems usually come from poor setup or inconsistent use rather than the toilet itself. Avoid these common mistakes:
- Buying before measuring: Always check access for sitting, cleaning and emptying.
- Ignoring ventilation: A poorly vented solids chamber is more likely to smell.
- Letting urine overflow: Empty early rather than waiting until the bottle is completely full.
- Using wet cover material: Dry material is key to odour control.
- Assuming it is maintenance-free: It still needs cleaning, checking and sensible waste handling.
So, Which is the Best Composting Toilet for Narrowboats?
For many narrowboats, the best option is a compact urine-diverting toilet with reliable ventilation, easy container removal and a footprint that suits the bathroom. If you live aboard, prioritise capacity, comfort and spare parts. If you cruise occasionally, a smaller or portable model may be enough.
A high-end marine-style unit can be a good choice if you want durability and a self-contained design. A simpler separating toilet may be better if you want fewer moving parts and a lower installation cost. The right answer is the one that fits your boat and your routine.
Before buying, sketch the layout, plan the vent, decide where waste will go and read the manufacturer’s instructions in full. A composting toilet is easiest to live with when the whole system has been planned, not just the toilet itself.
Frequently Asked Questions
Do composting toilets smell on narrowboats?
They should not smell strongly when used correctly. Good urine separation, dry cover material and effective ventilation are the main factors. Most odour problems come from liquid entering the solids chamber, poor airflow or containers being left too long.
Can I install a composting toilet myself?
Many practical boat owners can install a basic separating toilet, especially if no plumbing is required. However, cutting vents through the cabin side or roof needs care. If you are unsure, use a competent boat fitter.
How often do you empty a composting toilet?
It depends on the model, number of users and whether the boat is lived on full time. Urine usually needs emptying much more often than solids. Check the container daily at first until you understand your own pattern.
Do I need electricity for a composting toilet?
Not always. Some models are fully non-electric, while others use a small fan for ventilation. Fan-assisted toilets need a suitable power supply, usually 12V on a narrowboat, plus a safe external vent route.
Is a composting toilet better than a cassette toilet?
It depends on how you cruise and what maintenance you prefer. A cassette is familiar and easy to empty at Elsan points. A composting toilet can offer more independence, but it requires careful separation, storage planning and responsible disposal.
The best composting toilet for narrowboats is one that suits the boat, the crew and the way it will be used. Choose carefully, install it properly and keep the routine simple, and it can be a clean and practical part of life afloat.
