1. Correct Scupper Guards: All too
often the scuppers are either dangerously restricted by the
use of a plate with a few small round holes, or perhaps totally
unprotected. The logical arrangement is the use of a lightweight
cross, which prevents large objects, which could stop the scuppers,
from getting in and creates no measurable restrictions.
2. Cockpit Seat Scuppering: Inadequate
drainage of cockpit seats, which results in carrying undesirable
quantities of water inside the lee coaming, which is particularly
dangerous if there are related cockpit scat hatches. Even when
the cockpit is at deck level, it is no cure to cut through the
coaming, as this merely lets water in from the windward deck.
There should be large capacity scuppers, which can lead athwartships
outboard with a very minimum of pitch, as they only come into
effect when the boat is heeled in the direction of the scupper.
If the seat area can drain into a T-section of the cockpit well,
this is the best solution, as it provides almost unlimited capacity.
3. Coaming Locker Drains: A great many
boats have a useful and convenient locker in the wide type of
coaming, which is associated with the modern glass construction.
Again, there is no short cut to draining such lockers. You really
need an internal drain, with some filling, so that everything
in the locker tends to drain toward this scupper. Again, simply
cutting holes to the outside or into the cockpit seat area will
let in as much water as it lets out.
4. Pump Intake Screens: There are many
excellent diaphragm pumps, as exemplified by Edson, Hendcrson,
or Whale; and these pumps have a pretty good capability of handling
expected impurities, but this in no way helps the fact that
anything that gets into the pump intake may block the pump hose
before it ever gets to the pump itself, so that no matter how
invulnerable the pump is, as demonstrated at the Boat Show,
it is most important that there be a cross guard, or similar,
to prevent large objects from getting into the intake piping;
but without reducing the important maximum capacity of the pump.
5. Pump Discharge Routeing: Layout
of bilge pump discharge piping is a critical detail. There are
a great many boats which appear to leak in heavy weather; and,
in many cases, some of this water is coming in through the pump
system, as the pump valves themselves are not completely foolproof,
particularly in view of the fact that a certain amount of miscellaneous
solids can and will go out through the pump system, and these
may temporarily hold pump valves open. The only sure cure is
to have the pipe looped up high, close to the deck, and as near
the centerline as is feasible; and, where possible, pump discharges
should be above the waterline, which in turn will prevent any
tendency to siphon in; and will permit you to observe how well
the pump is operating.
6. Deck Bilge Pump Location: These
are all too often located inside of one of the cockpit seat
lockers, which is absolutely the last thing that you might be
able to open in an emergency in heavy weather at sea. Pumps
must be so located that they can be used without admitting any
water into the boat; and also so they can be cleaned or repaired;
again, without letting water in. The location should be near
the centerline, near the lazarette hatch; but arranged ideally
so they can be pumped through a tight gland in the after end
of the cockpit well, is perhaps ideal; and, hopefully, the location
should be so the helmsman can use it, so that in short-handed
sailing it is possible to be sure that the bilges are dry, without
having to go below to check. The second pump should be located
below deck, so that in extreme heavy weather it is possible
to pump without going on deck; and, in an emergency, both pumps
can be used at the same time. Ideally, they should be the same
type to minimize the requirement for spare parts; (In extreme
emergency, one pump can be cannibalised at a time when both
are out of operation, and it may permit you to come up with
one that is still useable.)
7. Sink Locations: Galley sinks and
toilet washbasins should not be located in a position where
they can temporarily go below the waterline under extreme heel.
It is not good enough to think that somebody is going to remember
to close some particular valve, quite apart from the fact that
with such valves closed the sink or washbasin could not be used.
In former times a washbasin well off the centerline could be
drained into a toilet bowl; but, with restrictions on toilet
discharges, this becomes less desirable. Sinks and washbasins
should be located near the centerline, and high enough so they
do not go below the waterline; and so that nobody has to remember.
In cases where the sink or basin is poorly located, there is
a temporary expedient, a spring loaded gate valve can be installed,
that is kept shut with the spring; but can be held open to permit
8. Toilet Bowl Height: Toilets should
be located with the edge of the bowl four to six inches above
the plane of flotation so that if the intake valve should fail,
there would be protection from flooding the boat.
9. Toilet Intake and Discharge: There
are too many instances where the toilet seawater intake is placed
either so high that it comes out of water in rough weather,
or perhaps heeled in one direction; and often it is located
too near the outlet, so that an undesirable amount of re-circulation
occurs when the boat is stationary. In general, the intake should
be low down, and reasonably near the centerline; and the outlet
higher up, and further aft.
10. Toilet Overboard Discharge: The
toilet discharge line should be looped well above the waterline,
and the loop should be kept inboard, so that it still performs
its protective function, even when the boat is heeled.
11. Tank Sounding: All tanks, both
water and fuel, should have provision for sounding; and appropriately
marked sticks should be furnished.
12. Tank Clearance: There should be
provision for cleaning all tanks, with the exception of gasoline
tanks, where any removable access plate would provide an undesirable
possibility for leakage.
13. Tank Vents: Tank vents seldom get
the thought they deserve. Fresh water tanks should never be
vented on deck; as this just provides a possibility of salt
water contamination. The vents should be located reasonably
near the centerline; and, if possible, arranged so they discharge
into a sink or washbasin that drains overboard, and there should
be a separate vent for each tank. It is then possible to make
very sure that each tank is completely filled by continuing
to take water, until the vent does overflow. On the other hand,
fuel tanks should invariably be vented to the deck; and in a
position where the normal flow of air would not carry smells
or vapors from the vent back into the cabin.
14. Through Hull Fittings: A well thought
out arrangement of all through-hull openings can add to the
safety, and ensure proper operation, as, for example, toilet
intake seacock must be in a point where it will be well below
the waterline, under all conditions. The same for the engine
cooling water intake. Overboard drainage from sinks and washbasins
should be straight, if possible, to facilitate cleaning, and
frequently a toilet intake can be tee'd to the same seacock
that is used for the basin drain. Cockpit scuppers, where possible,
should be above the waterline; this not only decreasing the
possibility of leaking, but also the location above the waterline
means that any fuel vapor in the cockpit will drain away. It
has already been mentioned that exhaust should be above the
waterline, even when going full speed; and that pump discharges
should be above the waterline, where they are visible. Finally,
seacocks should be located so that they are reasonably easy
to service, and to operate; and, in all cases, they should be
clearly marked in the full open and the full shut positions.
15. Fresh Water Check Valves: One of
the most universal shortcomings in the fresh water system is
failure to install a high-grade check valve in the lowest part
of the supply line leading to any galley or sink pumps. Such
a check valve keeps water in the line, and ensures satisfactory
operation of the pumps and eliminates many unnecessary strokes
otherwise required to get air out of the line.
Problem Areas, in: Yachting World Annual, 1973,
pagg. 43 e segg.