Bilge Pumps

[Dave A]

I''m replacing the bilge pump, the existing one came with the boat and I have no idea of it''s age, I will probably mount the old one in a higher position in the bilge as a back up. I have read the tests by "Pratical Sailor" and others but I can''t find any advice as to the size recommended for diferent sizes of boats, I have a Pearson 35. I would think that the largest one that will fit in the bilge would be the best choice but is this a reasonable assumption? Also the question of internal float switches comes up, most of the pumps listed do not have internal switches. My previous boat had an internal switch and I had no problems with it. Any suggestions from the board will be appreciated.

Thanks and fair winds,

Dave A

S/V Wind Song

[Irwin32]

I tend to agree that the largest pump that will fit is the one to use, provided you have the battery power to keep it working while you are away from your boat.

I have never owned a pump with an internal switch and will not buy one. I have found that I need to replace my float switch every 2 or 3 years. I would rather spend the $15 for a new float switch than for a whole pump.

I replace the float switch every 3 years regardless.

[Jonathan316]

There''s some excellent advice on bilge pumps here that''s worth your attention:

http://www.yachtsurvey.com/bilge_pumps.htm

Their perspective is healthy for your boat.

Jonathan

[Dave A]

Thanks for the information, the external switch now makes more sense, also everyone should read the artical Jonathan suggested. As far as sizing the artical confirms my feelings.

Any other opinions?

Thanks,

Dave A

S/V Wind Song

[Sasha_V]

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[hamiam]

i think the bilge pump test from practical-sailor is worth a read. All pumps are not created equal and virtually none of them pump anywhere near their rated capacity.

[wwilson]

Dave A.

It may be obvious, but worth noting anyway that the capacity of the pump will be throttled by the hose/outlet port diameter on your boat, unless you are planning a new through-hull. Most (not all) pumps come with 1.125" or .75" bibs. If the existing hose is .75" there will be little good in installing a 4000 GPH pump. Sorry - I don''t have handy the capacity for the hose sizes at given lengths - maybe someone else on this thread can supply. In any event, bigger is better only up to a point with .75" hose and through-hull fittings. Also as stated in hamiam''s reply, pump ratings are "optomistic". A rough rule of thumb is that a 3-ft lift (head) can decrease rated flow by as much as 50%.

Wayne