High Capacity Bilge Pumps (4000+gph)

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Paul Tychsen

Active member
Looking for advice regarding high capacity bilge pumps. I searched old posts but didn't find anything relevant to high capacity bilges.

I've spent my share on the fun stuff (decoys, guns, etc), now I figure it's time to put my money where it counts - safety. Nearly lost my 16' last year when waves filled the back while beach launching.

The new rig is an 18' mirrocraft deep v with a center console. It has a foam floor that is fiberglassed over. There's a great spot for the bilge in the stern where the foam floor is cut out. I'm contemplating putting in a 4000gph Rule bilge (http://www.coolebuys.com/-p-41421.html). I'm not worried about getting the day-to-day rain or other small amount of water out of the boat, I'm looking for something that would help in an emergency (though I know there is no bilge that will keep up with some tasks).

Any cons of putting in a huge bilge, such as a 4000, or even an 8000? I realize I will have a 2" or 3" hose coming out the side of the boat. It looks to pull 15.5a (the 4000gph model), I'm not sure if that means 2 minutes or 2 hours on a typical deep cycle marine battery....but perhaps battery power could be a problem with a huge bilge?

Also, would anyone recommend keeping a large capacity bilge in storage, ready to hook up to a battery with alligator clips in an emergency? - I'm thinking hardwiring it in would make the most sense....but maybe someone can speak from experience.

The advice is always much appreciated-
Paul
 
If you have a bilge pump in storage for when you really need it - it will never get used because there won't be enough time in an emergency to hook it up. Been there done that.

I don't think you could put a bilge pump in that is big enough to handle a real swamping if that's what you're worried about. Even a 6000 gph pump is only 16 gal every 10 sec if my math is right. 10 sec is a real long time in any emergency. Not to mention the battery power that you hope you have when the boat swamps and shorts out the battery or blows a fuse.

Stick with a normal sized pump like a 1000 gph and realize you might need to try harder to anticipate problem situations before they occur. Make sure you have enough life jackets and are wearing them.
 
I'm with Pete. If you are in situations where you expect swamping is possible and want to be prepared, I'd suggest you need to add floatation rather than bailing capacity. If you are not looking for something to get you out a trouble you expect, but something to keep your boat afloat when you put a hole in it, there is no pump with enough capacity. Carry floatation to wear and/or a life raft or survival suits.

On the canoe and kayak front, folks get very creative with various foam installations and inflatable float bags. Lots of whitewater rafts are self bailing, and some boat designs intended to be used in surf are simply shaped so they can't catch and hold water. (Think of a jet ski.)

Maybe we could camo one of these:


http://www.youtube.com/watch#!v=imD3p96eTuw&feature=fvw

Think of the seaducking opportunities!
 
Paul,
we use a couple of the 3700 to dewater sunk boats for salvage work. They will get the water out but not as fast as you would think. (Gas trash pumps work way faster). I dont think one would keep up with a 3 inch hole in a hull if you couldnt get to it to partially plug it up. Also the batteries must not go under or they will short out under a load like the pump.
The 1 1\2 discharge is easier to find flex hose for but 2 inch will give more flow. It would be way faster than buckets for getting a wave out.

15 amps is a lot and you want to size the wire for 3% voltage drop.
here is a link to a calculator for the wire size. http://beta.circuitwizard.bluesea.com/
on a cold day the battery is going to struggle to run that without charge help from the motor. Most small outboards only charge with about 15 amps or less.

It will work, but it is only one part of the big picture of your boat.
 
For those times when I need to bail out the boat fast I also carry a Seasense Hand Bilge Pump to supliment the elect bildge. The hand pump can move a lot of water and works even if I have a dead battery or blown fuse.
 
Paul-

I'm new to boats... but not pumps.

I guess the direction I would look at it is to try to determine displacement/volume of your boat (from the deck down for a total submersion) in cubic feet (There are 7.48 gallons/cubic foot) and then try to size a pump that would 1. not be too big (physically) and 2. move water at a rate that is comfortable to you and (not pumps.. but still a solution) 3. as has been said before, if possible try to offset air/water space with flotation foam so that it is less space for water to get in to quickly which will also help keep the boat from hopefully submerging and allowing that much more water in.... of course if you weigh any boat down with too much weight in gear you need to further offset the air space that much more... and creating space out of nothing hasn't been proven scientifically yet.

As to the pump... if you figure you have an area that is 4 feet by 6 feet by 2 feet (I'm just throwing numbers out) which is the deck area inside the boat.. that gives you 48 cubic feet = about 360 gallons. Your 4000 gph pump is going to empty that (so long as no more water is coming in) in 324 seconds or 5.4 minutes.

Anyways... those are the thoughts of an engineer.. take them for what they are worth. Me... I'll take a nice bilge pump... and a bucket.

Boat safe!

Erik
 
You would have to have an "AWFULL GASH" to warrant that size pump!! 1200 Is more than sufficient,I've had mirro lake fisherman's for years with rivets as loose can be!! If the s--t hits the fan,punch it and run it with the plug out!!!!!!
 
I have decided on two 1100gph Rules on seperate batteries. This seems to be a suitable compromise between overkill and average based on the feedback you all have provided. I appreciate your insight.

I also read through a couple old posts on VHF radios and will order an Icom M72 in the morning. One question - I know it's submersible, but does it float? Any better handheld models out there these days (it was an old post)?

Thanks-
Paul
 
I've used Icom radios for 20 years on pleasure boats and my off shore boats I love thier products,dependable and good performance,Good enough to use 100 miles plus out besides an SSB-you won't be dissapointed,YOU GET WHAT YOU PAY FOR!! Good luck!!
 
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