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The
Ancestral Latrine
On early sailing ships, the crew used the vessel's
sharp prow, which was known as the beak head, as an open-air
latrine. The latrine was named for its location - an appellation
that still survives, even though the head came in from the
cold more than a century ago.
Marine toilets or 'marine heads' as they are called, come in both
manual and electric versions. To keep the gaskets and the
valves of the pumps functioning smoothly during your bareboat charter,
simply pour in about a quarter of a cup of vegetable (cooking)
oil into the bowl of the marine toilet once daily and flush it through the
system.
The chief problem you could encounter (with a marine toilet)
is their cantankerous inclination to clog, especially if used
as receptacles for such objects as cigarette ends, tampons
or soap wrappers etc. To avoid an unpleasant job or an expensive service call, one or more important things for bareboat crew to remember on a bareboat charter yacht is that, with the exception of
toilet paper nothing goes into a marine toilet that has not passed
through your mouth first... a service call to clear
a blocked toilet will be charged to you...The most vulnerable
spot is usually the internal discharge valve that prevents
waste from being drawn back into the pump. This valve is known
as the joker - possibly a corruption of the word choker, because
anything that is lodged there effectively chokes the pump.
However the problem can be fixed with relative ease...just
open the joker and remove the obstruction...see the diagram
below.
To
remove foreign objects carelessly or inadvertently dropped
into the bowl of a marine toilet, unscrew the discharge tailpiece from the discharge
line and lift out the rubber joker valve. If the valve is
in sound condition, wipe it clean and reassemble the unit;
otherwise, replace it.

In a typical hand-operated marine toilet, the up-and-down
action of a pump circulates raw water and flushes waste into
the holding tank of a bareboat - or overboard - when the flush-valve lever
is opened.
If a manual pump handle is hard to operate - or an electric
pump seems balky - be sure the seacock is wide open and there
are no kinks in the intake and discharge lines. Movement of
your bareboat underway can shut the seacock or crimp the intake line,
thereby cutting off flow.
How the marine head works
The up-and-down action of a pump circulates raw water and
flushes the waste overboard or into a holding tank on your bareboat if a
manual pump handle is hard to operate - or an electric pump
seems balky - be sure the seacock is wide open and there are
no kinks in the intake and discharge line.
To use a marine head:
- Push the black lever to the 'wet bowl' position
and then pump until water enters the bowl.
- Use the marine toilet... after use, with the lever
still pushed to the 'wet bowl' position...pump for 15-20
strokes to evacuate the bowl and flush out the discharge
lines.
- Now push the lever to the 'dry bowl'
position...and pump the bowl dry.
The seacocks for both the 'sea water' inlet
and 'waste outlet' pipes in the sewerage bilge
are set in the open position at the commencement of bareboat charters...they
should not need adjusting in normal circumstances.
A
cutaway view of a manual toilet pump on your marine toilet traces movement of water
during the intake phase of operation and pinpoints maintenance
spots.
On the downstroke, as shown here, the piston
draws clean water through the intake valve, while forcing
waste water from the cylinder into the discharge line through
the joker valve.
On the upstroke the clean water will be forced
past the outlet valve and into the bowl. The upstroke also
draws a new charge of water and waste from the toilet bowl into the
cylinder.
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