Bilge pumps are primarily used for removing water from a kayak or canoe cockpit. As these boats fill up with water they become increasingly unstable, so bilge pumps provide a means for regaining stability and cleaning up after a wet exit. They can also be quite entertaining if used to squirt friends.
Fairly simple to operate, bilge pumps have a handle on top which gets raised and depressed in order to force water up the bottom opening of the tube. A rubber flap on the bottom of the handle allows water to be sucked up without being forced back out. As the pumping continues, the water gets propelled out the opening near the top of the tube. Bilge pumps can clear around eight gallons of water per minute.
A faster flow rate is achieved by using a higher capacity tube. The downside of a large tube is that the bilge pump will be slightly more bulky and harder to pump. Most bilge pumps can pump a rate of eight gallons of water per minute.
Many times a sponge will be needed to mop up the last remnants of water in the bottom of a boat, because the faster-flow pumps need at least an inch of water to work properly.
The most commonly broken part of a bilge pump is the shaft that connects the handle. When you are pumping it is challenging to press directly down on the handle, which can result in a bent shaft. An alloy shaft is recommended to prevent this from happening.
Other materials used in a bilge pump include a tube shell which is typically plastic, and a foam collar used for floatation if the pump gets tossed overboard. Some pumps come with a hose attachment for the output nozzle, but this isn't necessary because you don't need to move the water very far to get it out of a kayak or canoe.
