Manual bilge pump on 41DS?

Aug 11, 2020
9
Hunter 41 San Diego
While reading through the 41DS owners manual, I noticed a diagram showing a manual bilge pump located around the swim platform. But, other than the diagram, there is no mention of this pump in the manual. Anyone know how this pump is operated and how many gallons/minute it moves?
 

Nodak7

.
Sep 28, 2008
1,256
Hunter 41DS Punta Gorda, FL
The handle is in the Lazarette. The pump is located at the exit of the cockpit going to the swim platform. There is a little flapper door there. Lift it and put the handle in the reciever. It's a manual pump. The suction leads down to just at the lower electric bilge pump.
 
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Jul 6, 2017
158
Hunter H 41DS Hampton, VA
Like Nodak7 says. You should test it. The handle is a stainless rod and should be in the lazarette.

You should also have two electric bilge pumps as well. The low water regular one and and you should also have a high water high volume electric pump. It has an alarm associated with it. You can manually operate the built in float switch and the pump should run and the alarm will go off. The pump is located on the front step in the bilge. (I would never want to get in there to replace it) If you want to test it with water you can jamb the lower float switch closed and remove the raw water strainer bowl for the engine intake and open the sea cock, or run a hose down there.
 
Aug 11, 2020
9
Hunter 41 San Diego
Thanks for the replies. I'm about to purchase a 41DS and will test the pumps during the survey and yearly after that.

The Whale Gusher manual recommends replacing the rubber diaphragm every 3 years, which is seems conservative. And I assume the previous owner never replaced it, so I'll inspect the diaphragm to see how degraded it looks and replace it regardless.
 
Jul 6, 2017
158
Hunter H 41DS Hampton, VA
I'd be interested to know if anyone has actually ever saved their boat with a 17 GPM manual bilge pump? :)
 
Aug 11, 2020
9
Hunter 41 San Diego
Having a variety of ways to plug a hole is paramount. Wooden plugs, a tarp spread over the hull, even cotton rags. Once the flow is reduced, the bilge pumps have a chance to keep up until you make it to shore or help arrives.
 
Feb 21, 2013
4,638
Hunter 46 Point Richmond, CA
I'd be interested to know if anyone has actually ever saved their boat with a 17 GPM manual bilge pump? :)
Great question!!................never have but if you might be interested in estimating how fast the water is coming into your boat to determine whether you can displace it with both your manual and electric bilge pumps. You can impress your sailing friends by estimating how fast the water is coming into your boat with the Bernoulli equation simplified below:

1598539592233.png
 

Nodak7

.
Sep 28, 2008
1,256
Hunter 41DS Punta Gorda, FL
Great question!!................never have but if you might be interested in estimating how fast the water is coming into your boat to determine whether you can displace it with both your manual and electric bilge pumps. You can impress your sailing friends by estimating how fast the water is coming into your boat with the Bernoulli equation simplified below:

View attachment 184234
You probably ought to put the "adrenaline" factor in there as well! I can imagine you would be pumping to beat the band! LMAO thinking about it. Hopefully I (or anyone) never have to us it!
 
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Likes: sail sfbay
May 24, 2004
7,164
CC 30 South Florida
It is imperative that you test your manual pump. Have seen a couple that were crushed or incorrectly installed by the manufacturer. during construction. The pumps are the last line of defense, first locate the source of the water intrusion and plug it before you go to the pump..
 
Feb 21, 2013
4,638
Hunter 46 Point Richmond, CA
That is the area for a 1" diameter hole (0.785 sq in or 0.005454 sq ft). So if you use that area in sqft and say 4 feet of static head from the waterline to the hole and calculate it through you come up with 24 gallons per minute.

My sailboat has a primary Rule 1500 and secondary Rule 4000 electric bilge pump that can pump 25 and 67 gallon per minute, respectively. So one can conclude the primary bilge pump can discharge the inflow, calculated above, without the need for the secondary and manual bilge pump thereby allowing you time to plug the hole, if you can access it, OR get back to the dock or boat yard, as long as the hole is not any larger than 1 inch diameter. Seems like the combination of a primary and secondary electric and manual bilge pump was a good design by Hunter, albeit the next larger size manual pump (Gusher 30 that can pump 31 gallons per hour) would be helpful in the event the electric pumps failed with a 1 inch diameter hole.