Red WC sign onboard a boat.

A Beginner's Guide to a Boat's Onboard Toilet

January 29, 2025 | Maintenance | By: North Florida Yacht Sales

Red WC sign onboard a boat.Some boats come with an onboard toilet, which can drastically improve your voyage experience. No longer will you need to hunt for the nearest marina and take route detours to find a public bathroom! It makes longer boat trips much easier and overnight trips much more enjoyable.

You need to know the basics in order to make use of your boat’s onboard toilet, so keep reading to learn the essentials. If you have questions or want to shop boats for sale, chat with the friendly staff at North Florida Yacht Sales. Our dealership is based in Jacksonville, FL, and we also serve those in Palm Coast and Lakeside.

Understanding the Process of Using an Onboard Toilet

The first step is knowing how to use the boat's onboard toilet. Here, you will want to start by consulting the owner's manual. Your specific boat may have unique features, which are important to discover before usage.

Many boats rely on a manual toilet flushing system. As the name implies, this means you will need to do a bit of work to go through the process of removing waste from your onboard toilet.

There are two key parts involved: a handle and a switch. The handle is usually located on the right hand of the lavatory seat. The switch is usually located above the handle.

The switch will be in standby mode as the default, which is typically the right-hand side position. This keeps the onboard toilet safe from clogging by temporarily restricting the water intake valve.

In order to flush the boat’s onboard toilet, you will need to move the switch to the left-hand side position. This opens the water intake valve and lets in water.

Then, it's time to pump the handle. This gets water flowing and starts removing the contents in the lavatory. It typically takes about 10 pumps. When this is finished, move the switch back into the right-hand position. Then, pump about 10 more times. This helps provide support without bringing in more water. Repeat the process of pumping on both sides of the switch about three times. Because the boat’s outlet hose is long and curved, more effort and pressure are needed to move everything along.

Preventing Onboard Toilet Clogging

It's important to take steps to keep the boat’s onboard toilet from clogging. That's simply a headache you never want to deal with!

Make sure to understand the limits of your boat's onboard toilet system. Electric boat toilets, for example, cannot handle toilet paper. Their system involves a water intake pump, an outlet pump, and a spinning knife system. Any toilet paper tossed into the onboard toilet would quickly get stuck around the knives. This means you would need a wastebasket or bag to hold the used toilet paper (which would need to be changed daily for obvious reasons).

Next, you need to understand what water your boat’s onboard toilet system uses. Some boats will use seawater while others need freshwater. If your boat needs freshwater, make sure you know what water tank it comes from and monitor the water levels accordingly.

Finally, if your system can process toilet paper, avoid putting too much in at once. If you are boating with young kids, you may need to show them an example of the proper amount.

Disposing of Onboard Toilet Waste Properly

You'll eventually need to dispose of the boat’s onboard toilet waste - and there is a right way and a wrong way to do this.

Classic systems will be connected to the sea. Never dispose of onboard toilet waste in a calm bay or area where swimmers may be! You also won't want to dispose of onboard toilet waste when you are at a marina. Be considerate of others and save yourself some hassle by simply using a nearby public facility.

Some systems will connect the onboard toilets to waste tanks, which will need to be emptied regularly and far away from others. This should be done either daily or as needed.

We hope you found this guide to onboard boat toilets helpful. For more information or to shop boats for sale, reach out to the experts at North Florida Yacht Sales in Jacksonville, FL. We can answer questions, provide advice, and help with anything you need. Stop by today!



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