Types Of Toilets

Let’s talk toilets!

The choice of toilet on a boat is a rather personal thing, and the waterways are awash with people willing to express their opinion on the choice you should make.

So we will run through the main options and a few of the pros and cons.

Cassette Toilets

Those of you familiar with caravanning will be familiar with this type of toilet, basically it is a scaled up version of the old style camping “Porta Potti”.
The toilet is a self contained unit usually connected to the boats fresh water system to provide flushing water, the waste being collected in a sealed container (Cassette) in the base.
When the cassette needs to be emptied it can be removed with the minimum of fuss and emptied at a disposal point, it is possible to have a number of cartridges in reserve if a disposal point is not available.

PROS

• Cheap.
• Simple to install.
• Compact.
• Supposedly more places to empty a cassette when full than to get a waste tank pumped out. (Unfortunately I think we all know where this means.)

CONS

• Designs tend to be rather small and look distinctly “Caravany”.
• You still have to at some point have some involvement with “shh! you know what”.
• The cassettes don’t hold that much waste around 17 Ltr.
• The cassettes are heavy to lift on and off the boat.
• If you have spare cassettes where do you keep the full ones?

Drop Toilets

Any body familiar with boating twenty plus years ago will remember these.
These toilets roughly resemble domestic toilets and are usually made from the familiar porcelain, flushing water is provided from the boats fresh water system.
The flush is provided by an electric pump or a hand pump handle.
The toilet comes equipped with a foot peddle to open a “trap door” in the bottom of the bowl and gravity does the rest!
In days gone by before we all turned green the waste would drop through a hole in the bottom of the boat, but now a days it drops into a holding tank that can be pumped out when full.

PROS

• Cheapish.
• Fairly conventional in size and design.
• Simplicity very little to go wrong or get bunged up.
• Holding tank can have a large capacity, this makes it particularly suitable for hire fleets.

CONS

• Because the toilet needs to be located above the holding tank the boat needs to be designed around this tank.
• It is not usually practical to position the holding tank on the boats center line, so a full tank can adversely effect the boats trim.
• A pump out facility is needed to empty the holding tank.
• Pump out facilitys charge.
• This type of toilet unfortunately tends to smell. (A open trap door into a large tank of sloshing “Shh! you know what” means it’s unavoidable as the holding tank fills up.
• A certain amount of instruction in the use of the toilet is necessary.
• You want to avoid looking down that trapdoor!

Pump Out Toilet Systems

These toilets most closely resemble domestic toilets, in fact they are almost identical to European domestic toilets.
These toilets are connected to the boats fresh water system to provide flushing water, and the waste is transferred via a 32mm pipe to a central holding tank.
Various methods are used to speed the waste on its way to the holding tank, without going in to detail all of which are very efficient.
Many of these toilets provide long and short flush functions to conserve water and holding tank space.

PROS

• The nearest possible equivalent to a domestic toilet.
• Easy to locate.
• Large range of styles available.
• Holding tank can be located in any suitable position or on the boats center line if trim is important.
• More than one toilet can be plumbed to the holding tank.

Cons

• Not cheap, the cost of the holding tank and plumbing needs to be remembered.
• A fair amount of plumbing work is involved.
• On full flush they do use around 3 Ltr per flush.
• This type of toilet will get bunged if you flush things you shouldn’t!
• You need a pump out facility to empty the holding tank.
• Pump out facilitates charge.

Composting Toilet Systems

These toilets would seem the ideal green system for boats.
Composting toilets evaporate the liquids and odorlessly decompose the remaining waste into an inoffensive fertilising soil. (In theory!)

PROS

• No cassette or tank to pump out.
• Frees up the space normally taken by pump out tank.
• Environmentally friendly.
• Doesn’t use any water.

CONS

• Very much an unknown system in the boat world a few have been fitted but very little is said about them and most of that is negative.
• They are relatively pricey.
• They are large and ugly looking.
• They do need a AC or DC supply to work
• Although the waste is supposedly very environmentally friendly it will still need to go somewhere?
• A small amount of liquid is produced which needs to be collected and disposed of correctly.

What do we recommend?

Well the standard toilet in our boats is a Tecma pump out system. Most customers in recent years prefer these systems and concerns over the availability of pump out station is rapidly being addressed by BW and the private sector.
For a small extra cost our boats can be equipped with a self pump out system that will allow the boats black water tank to pumped into a conventional disposal point.

For the long term live aboard cruiser we would suggest the pump out system being backed up by a small inexpensive camping style “Porta Potti” for use in emergencies if you were to become icebound or a pump out facility was unavailable.

Why aren’t you fitting Vacuum Toilets?

Simple answers is we did and we wont be fitting anymore!

Something New

We are hoping to trial a new system soon that should allow for a boat to be fitted with a toilet of the sort used in a pump out system but incorporating only a small holding tank waste from this tank will then be automatically incinerated leaving only a small amount of ash to dispose of.

How the system works

After flushing, all toilet waste is passed through the macerator pump, which is then conveyed to the waste holding tank. A level sensor within the tank alerts the incinerator that there is waste requiring incineration and the incineration process begins.

A measured quantity of waste is pumped into the chamber and combustion commences, whereupon all contents of the chamber are incinerated leaving a sterile chamber. When the incineration process is complete combustion ceases and the incinerator begins its cool down cycle.

If the holding tank level sensor indicates there is still waste in the holding tank, further incinerations are initiated until the tank is empty.

The WC16 has the capability of incinerating up to 16 litres of waste per hour and larger models are available to cope with higher flow volumes.

The WC16 meets all required Environmental and Health and Safety regulations - details of which are available on request.

If you would like to be informed of how the trials go and further details when the system becomes available please contact us at