Select Page

There are a number of different types of marine toilet, or heads. They fall into one of three categories – manual, electric and vacuum, the most common being the manual, hand pumped type. These have double acting piston-pumps which both discharge the waste and flush the toilet with sea water.

Marine toilets have an inlet hose and outlet hose connected to seacocks, which need regular servicing. Toilets below the waterline must have a vented loop fitting to prevent water from being siphoned into the boat via a leaking inlet valve. The vented loop should be fitted above the level of the waterline according to manufacturer’s instructions. Allowance should be made for sailing boats where angle of heel which will change the level of the waterline.

The main issues that cause problems with the heads through the boating season are scale deposits, blockage and unpleasant odours.

Scale deposits

A build up of scale deposits in the hoses and toilet system cause the heads to become harder and harder to flush and the valves no longer function either. I have found the easiest way to avoid this happening is to flush the system with white vinegar from time to time. The vinegar dissolves the scale and will keep the problem under control.

One technique used is to remove the clogged pipes from the boat when it is in the boatyard and bash them against a wall or hard surface, which breaks down the calcium and this then falls out of the pipe.

Blockage

At some time or other most boat owners have had to deal with a marine toilet blockage or malfunction which they would rather forget about. This is seldom the fault of the system but more often than not is because an object other than human waste has been put in the toilet. Clear instructions need to be given to all those who come aboard how to use a marine toilet and these instructions should be provided in the heads also, to remind users and avoid embarrassment. Keeping a small waste bin in the heads is also advised.

Clearing a blockage in a manual toilet is done as follows:

  • Close both seacocks. Repeat, close both seacocks.
  • Follow instructions for servicing the pump.
  • Remove the pump and non-return valve in the discharge pipe, which will cause a leakage, so be ready with a bucket and sponge.
  • Clear any debris between the bowl and the non-return valve.
  • Check the pump for any debris.
  • If no debris has been found, the problem lies in the pipework to the seacock or holding tank if fitted.

Bad odours

The main source of bad odours comes from anaerobic bacteria which break down sewage. These bacteria do not need oxygen to live while aerobic bacteria, which also break down raw sewage, do. Keeping the system aerated is therefore desirable as non smelly aerobic bacteria will thrive. This can be done by ensuring holding tanks have proper air vents fitted and that stagnant effluent is not allowed to remain trapped in hoses. Chemical treatments are available as are fresh water flush systems.

Poor quality outlet hoses that are not of a recommended sanitary grade should not be fitted to a toilet system as odours can find their way through the piping, even if liquid does not. To check if a hose is the culprit, the easiest way to do this is to rub a clean cloth along it and then smell the cloth. The remedy here is to replace such permeable hoses with the correct grade, which may be expensive but necessary. If your boat does not have sanitary grade piping then this might be a boatyard job worth considering.

Leaks are another cause of bad smells, so it is worth keeping a check of all the joints in the sanitary system through the season, as the smallest leak will need to be dealt with.

Other causes of bad smells come from rotting organic matter such as seaweed and small marine organisms becoming trapped in the water inlet system or even in the toilet itself. One remedy for this is to fit a raw water strainer, similar to the strainers used for engines. Another is to get into the habit of doing fresh water flushes of the heads which entails closing the seacocks and connecting to fresh water in order to do so.

Winterisation

Marine toilets should be drained completely, both as protection against frost damage and to prevent anaerobic bacteria from growing in the pipework which causes unpleasant smells. Follow the manufacturer’s instructions on how to drain the system ashore, which typically include the following steps:

  • Open any secondary valves.
  • Remove the base drain plug.
  • Disconnect the discharge flange from the pump.
  • Loosen hose clips and disconnect the hose end from both seacock hose tails. Pump the handle to drain the toilet pump and ensure all water is drained from the toilet system.

Note: the use of anti-freeze is not recommended as it is impossible to ensure that it penetrates the complete toilet system. If it is used, it must be glycol based.

Marine sea Toilet

Servicing

Servicing the heads or replacing worn parts is not too horrendous a job when done ashore. Service kits and replacement parts are readily available and comparatively easy to instal – though with boats we all know that is easier said than done.

Manual heads have a pump with a system of valves and seals which need replacing periodically as they become worn or damaged by calcification. When this happens they begin to leak. A service every year or two, depending on usage, is advisable and service kits are available. Make sure you have the correct service kit for your model of toilet together with the manufacturer’s instructions. Here is a very abbreviated list of instructions to give an idea of what is involved:

  • Remove the pump assembly.
  • Dismantle the pump assembly.
  • Clean and disinfect all parts.
  • Remove scale.
  • Replace the piston O-ring and pump seals.
  • Replace top and bottom valve gaskets and the joker valve, unless in perfect condition.
  • Reassemble the pump, lubricating the cylinder bore with petroleum jelly.
  • Vent loop valves can sometimes become blocked by salt crystals in the line. It is therefore a good idea to unscrew the valve and wash it in warm water.

Essential Knots: Sheet bend

Essential Knots: Sheet bend Use: Joining two ropes together. A sheet bend is particularly useful for joining two ropes of different...

2023 Rolex Fastnet Race – Part 2

Simon Jollands took part in the 2023 Rolex Fastnet Race. This is the second of his articles on the race aboard Lancelot II, a Beneteau First 40.

Jester Challenge 2022 – Sailing single handed from Plymouth UK to the Azores: Part 6 – Communications

Jester Challenge – A modern experiment in old-fashioned self-reliance, self sufficiency, and personal responsibility. This is the sixth of a 10-part post where solo sailor, Bernie Branfield, shares his first-hand account of his single-handed, 2022 Jester Challenge, from Plymouth, UK to the Azores, in his 26′ Invicta Mk2, Louisa.

Winch Servicing

It is not essential to service the winches when a boat is ashore, but if time allows I prefer to do this maintenance job when the boat...

Boat interior inspection and checks

While a boat is ashore, the most critical interior checks to carry out are those that concern the safety of the boat. This entails the integrity of all through-hull fittings and seacocks, the gas system and the electrical system.

Peer to Peer yacht charter – How can you monetize your boat?

There is a growing trend in peer to peer yacht charter. How does it work? People already rent rooms, cars and bikes from one...

Gybing a sailing boat

Gybing is the sailing manoeuvre used to change a boat's direction through a following wind. As with the tacking manoeuvre,...

Tacking a sailing boat

Tacking is the sailing manoeuvre used to change a boat's direction through an oncoming wind. Tacking a sailing boat calls...

Nautical paper charts – a reminder of the basics

The nautical chart is an indispensable tool for navigation. A chart is a graphic representation of an area of the sea which might also include coastlines, estuaries and islands. All cruising leisure boats should carry up-to-date paper charts.

Repairing chips and dings in gelcoat

The gelcoat topsides of a GRP boat can be pampered and restored to their former glory relatively easily when it is ashore. Gelcoat is only a very thin outer layer of the hull, often less than 1mm thick, so you should avoid cleaning it with highly abrasive cleaners, or an-ything that could potentially damage its surface.

Passage Planning Advice & Safety for skippers

Passage planning helps you to: • Decide where to go • Calculate how long it will take to get there • Avoid bad weather •...

Boat interior varnishing

Most boat interiors have a combination of varnished and painted surfaces including solid wooden joinery, plywood laminates with thin hardwood veneers and glass reinforced plastic. When making your assessment of what you are going to do, bear in mind that the varnishing process consumes a lot of time, especially if the existing surfaces are in poor shape.

Points of Sailing

The course on which a boat is sailing can be described by its angle to the wind, not to be confused with its compass...

Weather forecasting resources and tips

All competent sailors need to have a good basic understanding of how to interpret a weather forecast. They also need to be able to interpret the actual conditions they are experiencing.

ColRegs – avoiding collisions at sea

ColRegs - avoiding collisions at sea ColRegs Rule 8: Action to avoid collision (a) Any action taken to avoid collision shall...

Sailing to windward – how to take advantage of wind shifts

For most sailors, sailing upwind is the most exhilarating point of sail as you tack your way to your destination. Sailing to windward is a bit like zig-zagging your way up a mountain road through a series of hairpin bends – great fun but also calling for concentration and hard work.

Essential yacht tender safety for skippers and crew

Essential yacht tender safety - the dangers inherent in using a dinghy to get ashore from a moored or anchored yacht are all too easily...

Dag Pike’s Boat Survey

We're really pleased to be working with Dag Pike on some great new apps for iPhone & Android. Here'a a bit more about the first app: Dag Pike's...

Marine diesel exhaust checks

You should inspect the exhaust system for corrosion damage regularly, especially around the injection bend. If you have noticed the engine exhaust smoking a lot during the sailing season this can also indicate a number of potential problems.

Boating Rules of the Road – International ColRegs

    International ColRegs Rule 7: Risk of Collision Anyone who is responsible for a vessel at sea, from the...

First Aid Afloat – fish spine injury

First Aid Afloat - Here is what to do if somebody stands on a fish spine: • Check for dangers. Is it safe for you to enter...

Boating emergency – how to broadcast a MAYDAY emergency call

How to broadcast a MAYDAY emergency call   How to broadcast a MAYDAY emergency call if a vessel or person is in grave...

Wooden Hulls – Part 1

Traditional wooden boats have a plank on frame construction, a centuries old boat building method that is still in use today. Variations of the traditional method include carvel, clinker and strip planking, which all relate to the way the planking is attached to the frame.

Boat maintenance – what does it involve?

The maintenance of a boat involves things like cleaning, varnishing, painting, polishing, antifouling, servicing the engine, servicing the seacocks, and maintaining the gas and plumbing systems. It all amounts to a fairly considerable amount of work that can’t be ignored if you are to keep your boat in a safe and good condition.

Avoiding personal dangers at sea

In order to stay safe at sea, we need to know the risks we are facing and to be aware of any personal dangers we could possibly encounter. Here are six of the most common potential dangers individual crew members should be aware of.