Marine Toilet Guide: Manual, Electric Macerating or Portable Boat Toilet?
Choosing a marine toilet starts with how the boat is used and what it already has: room for a head compartment, a holding tank, a fresh water system and the battery power to run an electric flush. The three main types are the manual toilet, the electric macerating toilet and the portable toilet. This guide compares them using the manufacturer specifications for the Groco, Thetford and Dometic MasterFlush toilets we carry.
The short answer
- Simple, no electrical load, works with flat batteries: a manual toilet such as the Groco K Series, flushed with a hand pump.
- Push-button comfort and a home-style bowl: an electric macerating toilet such as the Dometic MasterFlush or the compact Thetford Nano.
- No plumbing at all, a small boat or a center console: a portable toilet such as the Thetford Porta Potti, with its own holding tank that you carry off and empty.
Manual marine toilets
A manual toilet uses a hand pump to bring in flush water and push waste out to the holding tank. It needs no power, has few parts to fail and keeps working if the batteries are down. The Groco K Series is a heavy duty example: a house-size bowl, an all bronze pump with a 3″ piston and adjustable flow up to 4 GPM. A foot pedal controls the flush water and shuts the inlet off automatically when released, so there are no valves to close or hand wheels to turn, and Groco rates it for installation above or below the waterline.
Electric macerating toilets
An electric macerating toilet flushes at the push of a button. A macerator pump grinds the waste before sending it to the holding tank, which gives a clean bowl and a more home-like experience. It uses battery power for every flush, so it fits boats with a healthy house bank.
Dometic MasterFlush. The 7000 Series uses Dometic’s Orbit base, which rotates 360 degrees around the bowl so the toilet fits tight heads and awkward plumbing runs, and Dometic designed it for retrofitting into small boats. The MF 7120 flushes with fresh water through an electric water valve built into the base and has a slow-close seat; the 7160 flushes with raw water. The MasterFlush 8740 is the premium option: a standard-height ceramic toilet with a residential-size bowl, an elongated slow-close seat, Normal and Low flush settings, through-the-floor or through-the-wall discharge and a Flush Touch Pad. Dometic lists it at 21.5″ deep, 19″ high and 14.75″ wide.
Thetford Nano. The Nano is Thetford’s compact macerating toilet for smaller heads. Thetford lists two check valves combined with a water trap to keep odors out, a quiet flush, and the option to flush with raw water or pressurized fresh water. It works with an Eco rocker switch, designed to cut energy and water use, or a smart flush controller. We carry the Nano Touch toilet on its own (controls sold separately), the Freshwater Kit and the Raw Water Kit with inlet pump.
Raw water vs fresh water flush
A raw water toilet pumps seawater in through a thru-hull to flush. It never draws down your fresh water tank, but seawater left standing in the lines can start to smell as marine growth inside dies off. A fresh water toilet flushes from the boat’s pressurized fresh water system, which keeps the lines cleaner and usually smells less, at the cost of using water from the tank. Some models, like the Thetford Nano and the MasterFlush 8740, can be set up either way.
Portable marine toilets
A portable toilet has no plumbing: a bowl on top of its own sealed holding tank that you carry off the boat and empty ashore. It is the simplest answer for day boats, center consoles and pontoons. The Thetford Porta Potti 135 flushes with a bellows pump, has a rotating pour-out spout and a sealed valve that keeps odors in the tank, and comes with a hold down kit that secures it to the deck.
Holding tanks and discharge rules
Untreated sewage cannot be discharged in US waters within three miles of shore, and the Florida Keys are a No Discharge Zone. Most installed toilets on recreational boats send waste to a holding tank that is emptied at a pump-out station. Pumps such as the Whale Gulper, which Whale describes as virtually unblockable and able to run dry, and the Shurflo 13 GPM macerator pump, built for waste evacuation, handle the plumbing side. For Jabsco 37010 Series electric toilets we also stock the complete motor and pump assembly in 12V and 24V.
Is a manual or electric marine toilet better?
It depends on the boat. A manual toilet needs no power, has fewer parts and keeps working when the batteries are low, so it suits smaller boats and owners who want simplicity. An electric macerating toilet flushes at the push of a button and feels more like a toilet at home, but it uses battery power for every flush and has a motor and pump to maintain.
What is the difference between a raw water and a fresh water marine toilet?
A raw water toilet flushes with seawater pumped in through a thru-hull, so it does not use the fresh water tank, but the standing seawater in the lines can cause odors. A fresh water toilet flushes from the boat’s pressurized fresh water system, which keeps the lines cleaner and reduces odor, but it draws from the tank. Some toilets, such as the Thetford Nano, can use either.
What is a macerating marine toilet?
A macerating toilet is an electric toilet with a pump that grinds waste into a slurry before sending it to the holding tank or discharge. It flushes at the push of a button, clears the bowl completely and moves waste easily through the discharge hose. Examples include the Dometic MasterFlush and Thetford Nano toilets.
Do I need a holding tank for a boat toilet?
For an installed toilet, in practice yes. Untreated sewage cannot be discharged within three miles of the US coast, and the Florida Keys are a No Discharge Zone, so installed toilets usually send waste to a holding tank that is emptied at a pump-out station. A portable toilet such as the Thetford Porta Potti has its own built-in tank that you empty ashore.
Shop marine toilets
Every toilet above is in our Marine Toilets category, and pumps are in Marine Pumps. Not sure which toilet fits your head? Call (786) 277-2596 with the space you have and whether the boat has a holding tank and fresh water pressure, and we will help you choose.