Features January 2018 Issue

Bilge Pump Basics to Keep Your Boat Afloat


Our research into bilge pumps and associated equipment stretches back several decades with the most recent bilge pump tests taking place in 2010 (See PS September 2010, and October 2010 online). When selecting a pump, keep in mind that sailboats rarely meet the ideal flow rate.

1. Test the operation of all bilge pump systems at regular intervals—twice annually at a minimum. Testing should verify the actual pumping of water overboard, rather than (in the case of electric pumps) simply switching the pump on and listening for motor operation.

2. Make sure all bilge pumps not only have intake strainers or strum boxes installed, but that they can be easily reached and cleared of debris. As a marine surveyor I often see centrifugal style pumps mounted beneath engines and completely inaccessible, even to simply clean the strainer—if your boat has similarly inaccessible pumps, relocate them for better access.

3. Larger capacity back-up pumps and their associated float switch should be mounted 4 to 6 inches higher than the primary pump. This lets the smallest pump take care of normal accumulations of water (with less battery drain) while allowing the larger ones to kick in only when needed. It also prevents the back-up pump from resting in the normal accumulation of bilge water, where it can become clogged with sludge and debris or seized from disuse.

4. List bilge pump by type, location and size for future reference and make sure there are spare parts or complete rebuild kits onboard for each. If you really want to go the extra mile, pack a complete spare pump assembly. Being able to swap out a defective pump lets you quickly bring the system back up, while giving you the option of repairing the damaged pump later at your convenience.

For a more detailed discussion of bilge pump installation and maintenance see “Bilge Pump Maintenance and Installation Tips,” at the Inside Practical Sailor blog at www.practical-sailor.com/blog. — FKL

Comments (1)

What timely advice! I am ashamed to say that my 30' sailboat has not been attended to as rigorously as needed. A week ago I thought I would check the bilges. To my real horror they were full! Not quite to overflowing but definitely nearing that situation. Pumped them as dry as I could with a small manual pump (16 gallons, approx) left the covers open and will revisit to see if they remain free of water. Looks like the pumps have stopped working automatically although one responds when switched to Manual mode. Lots of work ahead I am afraid. I recommend that sailors carry a manual pump since the emergency pump on the boat is questionable. In most cases, where water is gathering in the bilge due to the many sources that drain in the manual can do the job. In an emergency at sea the gathering of large amounts of water in the bilges and on the lower decks can be dealt with, at least for the moment, with a little transfer pump operating on 12V power but skippers must set up for this ahead of time and practice when no immediate danger exists. Wayne makes a nice little 1/10th hp unit that moves a lot of water. Thanks again for this vital information and the reminder.

Posted by: MRBLIGH | October 14, 2019 11:48 AM    Report this comment

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