
Onboard toilets are an indispensable part of a boat's equipment and crucial for well-being on the high seas. Toilets that are complicated to use or leak can significantly reduce the satisfaction of boating. Not only are the odors unpleasant in some circumstances, but there is also the risk of not being able to use the toilet at all. Laymen often believe the myth that with marine toilets, human metabolic products flow directly into the sea after flushing. Of course, this is not always the case. Rather, there are numerous types of on-board toilets available today, all of which offer different advantages and disadvantages. Here you can learn all about the different types of seawater toilets and how to use each.

Mechanical on-board toilet
The manual on-board toilet does not have a conventional flush like the toilet in your home. On the side of the on-board toilet there is a switch for pumping, another switch for flushing and a pump lever.
In order for the human feces to be pumped out, one flips the switch for pumping out and simultaneously operates the pump lever. By flipping the lever, the entire contents of the toilet are pumped out.
With the lever you can run water at the same time to flush down the feces. If you want to pump the toilet bowl empty afterwards, you should set the switch back to "pump down" and manually refill it five times. After the pump lever is locked, the on-board toilet is ready for the next operation.

Electric on-board toilet
An electric on-board toilet works in a similar way to a manual seawater toilet. The difference lies in the handling: Instead of the manual hand pump, the electric system takes over the pumping. Therefore, the electric marine toilet does not have a pump lever, but only two switches for pumping and flushing. In the field of electric toilets for sailors, there are various models that differ in their comfort.
1) Entry level models
Electric marine toilets are available, for example, as entry-level models with submersible pumps. The on-board toilets with chopper have both chopper and impeller pumps integrated.
2) Household style electric on-board toilet
In addition, there are electronic on-board toilets of household design, so that the pump is already installed in the porcelain bowl. At the same time there is the possibility of additional insulation. In this form of electric toilet water and energy consumption depends on the flushing time. This is determined by the duration of operation of the flush button.
3) Electric on-board toilets in modern designs.
The latest models of electric on-board toilets have large choppers with a diameter of 80 to 120 millimeters and a quiet motor. The noise level is comparable to that of a standard household toilet. Water consumption ranges from 1.5 to three liters per flush. In addition, most models can be used in conjunction with a holding tank without any problems.

Chemical toilets
In addition to the described models, you can also opt for chemical toilets, which are considered the ideal solution for small boats with limited space. The small on-board toilets take up little space and do not require a power supply or an external water or waste tank. However, the chemical toilet is only recommended for short trips, as the capacity is limited.
How to empty the on-board toilet?
Emptying at sea depends on the position of the toilets and holding tank in relation to the waterline:
- Below the waterline, the use requires a lye pump to evacuate the water through the board passage
- For on-board toilets above the waterline and the tank below the same, a drain pump is required
- If the tank is horizontal, a pump must be used to evacuate the wastewater
- If the tank is vertical and 50 centimeters above the waterline, it can be emptied by gravity
FREQUENTLY ASKED QUESTIONS- FAQs
What are the different names for on-board toilets?
On-board toilets are also known as "water closets", "seawater toilets" or "boat toilets".
What must not be disposed of in on-board toilets?
Only faeces and toilet paper are allowed in the on-board toilets. Rubbish or hygiene articles have no place in the on-board toilets.