The Lowly Bilge Pump – Some Helpful Tips

A good friend of mine once told me about water in boats. He said that he didn’t mind too much if his boat leaked a bit from the top down, but it was a different matter altogether if it leaked from the bottom up.

Few of us boaters do our bilge pumps the honor of regular service. These wonderful devices are designed to evacuate normal bilge water accumulation. When I say normal, I mean a well adjusted propeller shaft packing gland that drips a bit, not one that looks like a public water fountain satisfying a thirsty passerby, or a rudder gland that may trickle a bit in a strong following sea. Maybe the cockpit lockers or engine drops when things are a bit sloppy. You know, normal ingress, not the artisan wells of plumbing neglect. Someone once said the best bilge pump is a frightened man with a five gallon bucket. How many of us have been there’! You can put your hands down now. Any of us who have been at this for awhile have had to deal with copious amounts of the wet stuff at less than opportune times. My dear sister once came on deck while crossing the Yellow Banks in the Bahamas and said, “Neil, are the floor boards supposed to float”? It depends was my answer, not wanting to sound alarmed. The bilge pump discharge had back siphoned through a lee discharge with no siphon break. What a mess our food stuffs were below seat lockers. We had mystery meals for months, thanks to the labels on all our canned goods falling off. One of the down sides of building your own boat, you can only blame the builder.

This is the school of hard knocks. Well, enough of this, let’s get down in the deep dark recesses and have a look at this wonderful device. I always look at the float switch to see that it’s mounted on the centerline and not athwartships where normal smooth motion will cause rapid cycle when the bilge water sloshes from side to side. Are the bilges clean and debris free, or is there years of old paint, hair, dirt and lost tools just hoping to penetrate the usually wide open picket fence normal bilge pump strainer basket. Are the wiring connections in good order or are they starting to be as green as St. Patrick’s day. Lift those wet boys up and consider installing a proper terminal strip in lieu of those gummy black taped connections. This also helps when it comes to replacing this wondrous device. Simply loosen several terminal strip screws and wallah! No more cut, cut, cut and all the while the circuit gets shorter and shorter.

Recently I attended a boat that took a deep drink of water and discovered that a plastic tie wrap had wrapped itself around the impeller rotor which locked and caused quite a mess. You need to get on some grubbies and muck that stuff out occasionally. You’d be surprised how sweet your little boat can smell with a properly cleaned basement not to mention retrieving your long lost favorite tool that was mysteriously eaten by your good ship. Snap the pump off its strainer and check to see if the rotor is clear. Hair will foul a rotor and eventually lock up the small GPH varieties. Look at your hoses and clamps to see if renewal is in order. That hose with the little rings makes neat noises if whirled around a child’s head in a circular motion, but in my way of thinking has no value what soever on a boat. I have lost track of the number of times that when surveyed, this type hose was pumping more water in through perforations than it was pumping overboard. It just sort of recycles the stuff you want to get rid of.

God forbid if your discharge is below the waterline because you may be in for a large wet loss if this is the case.

The following are American Boating and Yacht Council’s H.22.7 recommended practices covering location and installation:

A. Bilge pumps shall be mounted in an accessible location to permit servicing and cleaning of the intake and/or screening.

B. The bilge pump inlet shall be located so that excess bilge water can be removed at normal boat trims. multiple pumps or manifolding may be used.

C. Pump intakes shall be protected to prevent ingestion of debris that are likely to cause pump failure.

D. Intake tubing, if used, shall not collapse under maximum pump suction.

E. Pump discharge systems shall be as nonrestrictive as practicable.

NOTE: Pump discharge capacity as installed may be reduced by such factors as:
-length of discharge piping.
-number and radius of bends.
-roughness J the interior surfaces of piping andfittings, and
-reduction in cross-sectional area of discharge system components such as check valves and thru-hulls.

F. The discharge location shall be above the waterline created by maximum conditions of the boat’s loading, heel, trim and motion astern.

EXCEPTION: The discharge may be located below the waterline if the discharge line is provided with a vented loop to prevent siphoning into the boat. A check valve shall not be used for this purpose.

G. A check valve may be used, if necessary, to prevent an automatic bilge pump from cycling on-and-off due to backflow from the discharge line.

H. Hose connections shall be secured with a non-corrosive type of clamp.

I. Motors of non-submersible bilge pumps shall be located above the maximum anticipated bile water level.

J. Automatically controlled pumps shall be installed with an overriding manual switch which is readily accessible.

K. Manually controlled pumps shall be installed with a switch which is readily accessible.

A 2″ hole 2′ below the waterline will allow in approximately 7,000 GPH in, and the most moderate sized vessel’s we look at do not have the pump capacity to void that much water. The bilge pump coupled with a visual or audible device can give you enough time to preform damage control before your good ship starts to experience negative buoyancy and starts down like a greased safe. Look at your vessel’s plumbing system with a critical eye and if in doubt, replace the questionable component. You won’t regret it. Sleep sound. Sleep dry and thank God he loves sailors.

Capt. Neil K. Haynes November 8, 1996

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