Bilge Business

I’m reading a book called "The Voyager’s Handbook" by Beth Leonard.  It’s a extremely thorough collection of all the stuff you need to know about offshore cruising aboard a sailboat.  Somewhere near the beginning; after crew considerations, choosing and financing your boat, and before sails and sail handling is a chapter on upgrading the boat for offshore.  Therein is a recommendation to have a manual bilge pump below deck that will pump at least thirty gallons per minute.  This is in addition to an automatic (DC powered) bilge pump.  There are good reasons to have a manual bilge pump below deck: it will work when all power is lost, it will be out of the elements, and it can be within reach of the VHF radio at the nav station.

Quijote has an automatic bilge pump that will pull water out of the bilge at 67 gallons per minute.  She also has a 20 gallon/minute manual bilge pump in the cockpit where a single hander will be able to steer and pump at the same time.   Those two pumps mostly meet the book's recommendations.  While the manual pump is out in the elements and puts out less than the recommended thirty gallons/minute, it is in reach of the wired VHF remote  at the helm.  Still, I began to consider supplementing the manual throughput by adding a second manual bilge pump below deck.

I was loathe to be adding any additional through-hull valves for that purpose, but what if I tee’d into the existing bilge pump plumbing.  To that end, I spent the better part of a day investigating the feasibility of adding a second manual bilge pump.  I looked into making room for a new hose that follows the existing manual pump plumbing and discovered very little additional room in some key constrictive places.  I also found few places below deck that would not be awkward to operate or consume precious storage space.

It occurred to me after several hours of pondering and scrabbling about, that teeing into the existing manual pump plumbing is a dumb idea anyway.  If I lose power and need to pump manually, I don’t want the choice of pumping in the cockpit or below deck; I want to be able to use both manual pumps if I can.  That being the case, I want to be teeing into the automatic pump plumbing.  As luck would have it, that turns out to be a much less invasive change, since the plumbing runs through a forward locker rather than squeezing between heating ducts and hot water hoses in the engine room as the existing manual pump plumbing does.

It also turns out that a twenty gallon manual pump is about a fifth of the cost of a thirty gallon pump and takes up a lot less space.  If I buy a second identical 20 gallon pump that taps into the automatic pump’s plumbing, then the manual pumps are interchangeable, I need only one spare, and I get forty gallons per minute when the power is out.  If the power is not out, I’ll have the 67 plus 20 gallons per minute I have now.

So that’s the plan.  I still need to do a little research, maybe use a check valve or two to prevent back pressure from one pump to the other, but it is a change that should be relatively easy and affordable.