Virtually all boats end up with unwanted water in the bilge, which must be removed. Water gets in from a propeller shaft packing gland, a leaky portlight, leaky seams in a wood boat, melting ice from the icebox and a multitude of other sources.
Leaving large amounts of water in the bilge can have several undesirable effects on your boat, including destabilizing it, lifting spilled fuel and distributing it throughout the bilge (where it can attack, among other things, the insulation on electrical wiring) and promoting the development of osmotic blisters in fiberglass hulls. And did we mention having the boat sink? Getting this water (we call it nuisance water) out of your boat is the primary function of a bilge pump.
What type of boat do you have?
Small Powerboats
Planing runabouts and ski boats use one submersible pump located aft. Small boats with large cockpits or low freeboard need bigger pumps.
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Boat Length
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Pump Output - Liter Per Hour
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To 5.4 m
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1100 -1900
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5,5 m – 7 m
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1700 - 2650
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7 m – 8 m
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2600 - 4100
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Sailboats
Medium and large sailboats use multiple manual and automatic pumps.
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Boat Length
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Pump Output - Liter Per Hour
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6,5 m – 8 m
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2300 - 3000
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8 m – 9 m
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3000 - 3800
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9 m – 10,5 m
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3800 - 6000
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10,5 m – 12,2 m
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6000 - 8300
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12,2 m – 14 m
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8300 - 15100
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Large Powerboats
Larger powerboats use one or more pumps. Each compartment that can hold water needs its own pump. Engine driven pump or second, larger electric pump recommended for emergency backup, especially for open water boating.
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Boat Length
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Pump Output - Liter Per Hour
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8m – 9m
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3000 - 4000
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9m – 10,5m
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3800 - 6000
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10,5m – 12,2m
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6000 - 8300
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12,2m – 14m
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8300 - 15100
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Manual or electric power?
High-capacity centrifugal pumps are relatively inexpensive and the easiest pumps to install, but they are rendered ineffective if your boat’s electrical system fails, and this is a likely occurrence if your boat takes on a lot of water. For this reason we recommend that, in addition to any electric pumps, you have at least one high-capacity manual diaphragm pump. Manual pumps can move substantial amounts of water (up to 76 Liter per minute or so).
Dual bilge pump installation
13200 l/h (or larger) emergency pump located above sump, and connected to manual switch. 1500 l/h (or smaller) pump with integral float switch, connected directly to battery.
