Get Your Head Checked

Posted: October 1, 2012

Follow this primer to upgrade your marine toilet.

By: Frank Lanier

While it’s often said the two best days of a boat owner’s life are when buying and selling, there’s a third happy time that ranks right up there — the day that ancient, temperamental marine toilet gets replaced with a modern, efficient unit.

Although the number of marine heads may seem overwhelming at first, there are really five types in common use: gravity feed, manual pump, macerating, vacuum and composting.

Gravity-feed toilets work just as the name implies, with the unit positioned directly above a holding tank, which can be separate or integral to the unit. Porta Potties are a common example. Bowl contents drain directly into a removable tank (typically from 2 to 5 gallons), which is later removed and dumped in the appropriate receptacle ashore. Flush water (if provided) is supplied by an internal reservoir, and while most require no plumbing, some larger units can be plumbed to draw flush water from the vessel’s freshwater system to a deck pumpout.

Prices for basic portable toilets begin around $100. The Marine Traveler by SeaLand ($500) is an upgraded version that uses pressure water from the vessel’s freshwater system and features a 9-gallon tank and a deck pumpout.

Manual-pump toilets utilize an integral hand pump to bring “raw” water into the bowl, where it mixes with the sewage and is then pumped clear. Installation requirements include a below-the-waterline through-hull fitting (for flush water), a seacock, a holding tank and pumpout options (deck and/or overboard, depending on the vessel’s area of operation) as well as the various hoses, fittings, etc., needed to connect each. Some manual units also offer the option of conversion to an electric pump. Par, Groco, Wilcox-Crittendon and Raritan are all well-known manufacturers of this type of system. Prices range from around $170 to more than $500.

Macerating toilets are designed to puree solid waste, much like a garbage disposal. This is typically accomplished by an electric-powered “grinder” (aka macerator) that uses blades to simultaneously chop and pump waste clear of the bowl. Flush water can be raw or from the vessel’s onboard freshwater system.

Jet-action heads, such as the Royal Flush by Headhunter, use pressurized water jets to macerate waste. The price of a standard electric macerating toilet starts at around $450.

Vacuum heads use an electric or manual pump to generate a vacuum in the system, which pulls sewage from the bowl to its final destination when the toilet is flushed (a holding tank or overboard). The SeaLand/Dometic VacuFlush system is an industry standard in the electric vacuum head market. The Blake Lavac ($440) is a good example of a manual vacuum head, but it also can be configured with an electric pump.

If you’re committed to having a “green” yacht, composting toilets use peat moss to turn waste into compost. As they’re completely self-contained, they can be an attractive alternative to traditional toilets. No plumbing is needed; however, they do require you to install a fan and a vent pipe.

Although early units were large and bulky, newer models such as the Air Head ($970) have the same footprint as a standard toilet, making them a viable choice.

General Installation Tips

Although you’ll always want to follow the manufacturer’s instructions (which will list specific requirements for a particular system) the following tips will apply to most any toilet installation:


- Select a location that provides sufficient clearance around and above the toilet, ensuring there is room to operate the pump (if manual), conduct maintenance, etc.

- Make sure the seat and lid can swing up and over at least 110 degrees (to prevent closing when the vessel heels or pitches).


- Select a mounting surface that’s flat, rigid and strong enough to provide adequate support.

- The support area should be at least 2-3 inches wider and deeper than the base of the toilet and have sufficient clearance below the mounting surface to access and secure the mounting bolt hardware.

- Use properly sized, marine-grade mounting hardware: stainless steel through-bolts, washers, self-locking nuts, etc.


- Use marine-grade, spiral-reinforced, smooth-bore flexible hoses for both inlet and discharge.

- Secure all hose runs against movement, provide chafe protection as needed and install the hoses so they do not exert any leverage on toilet fittings (to avoid leaks later on).

- Keep all hose runs as short as possible and avoid sharp bends.

- Install double marine-grade stainless steel hose clamps at each fitting.

- Install vented loops (as required) to prevent flooding.

Finally, keep in mind that your toilet is only one part of your vessel’s sanitation system. Correct installation and maintenance of the system as a whole is essential for proper, long-term operation and reliability.


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