Electric Bilge Pump

Apologies to Ness for side tracking her TR over on the discussion forum with questions about bilge pumps. Clarion provided the following info about his pump installation, and I am copying it here in hopes it will be archived.

These are responses to me asking about the installation of bilge pumps in their whitewater canoes. Seems like the advice would also apply to putting a pump in a sea kayak.

I would be interested in others’ advice as well, so please feel free to pitch in. I am particularly interested in a pump I heard about that does not need a switch–apparently turns on periodically, senses if there is water to be pumped, and turns itself off if there is no water. Eliminating the switch will eliminate a possible failure point, so the idea of this pump appeals to me. Copied info follows:


But pblanc posted a link to someone who did a very nice job of documenting it. I don’t have that link right now. Maybe p will post it again.

I’ll take a stab at explaining it though. It’s really very simple. And I have a link to some photos too.

Pump: Everyone seems to have settled on the Atwood Tsunami 1200. So that’s easy, and you can walk into Walmart and buy one. They’re like $37

Battery: I can only speak to the least expensive and easiest to work with, 12V SLA (sealed lead acid). Apparently anything over 3ah (amp hours) is fine. I got 5ah just to be sure, and I’m running 2 pumps. Here is the battery I got: http://www.batteriesasap.com/in12v5ahf2ba.html

Case: The case and battery kind of go hand in hand. This case is pretty much the perfect size for the battery I got: http://www.amazon.com/Outdoor-Products-Small-Watertight-Box/dp/B001AZR868 You used to be able to walk into Wal Mart and buy these cases but now all I’m finding are the large ones. But you can order them at the link I provided above.

You’ll also need a trickle charger. I can’t show you where I got mine because it was kind of a custom-job that someone gave me. I would try to order the charger and battery from the same place and save the postage. Johnny will hopefully see this and post his source for getting both.

Also need,

1 1/8 ID bilge pump hose (Lowes or a marine store),

5 amp fusable link and

Switch: available at wallmart or auto parts store. I also bought a rubber boot. It screws over the switch to make it somewhat water proof. I also smeared silicone around the switch and where the wires come through the box. I drilled a separate hole for each wire.

I took pics and added them to webshots. Scroll down a bit below each pics to read my brief comments.


Make sure you wire the pump’s brown wire to the positive terminal. Put the 5 amp fuse link in that leg just before the battery positive side. It goes in the box.

The pump’s black wire leg gets the switch between the pump and the battery negative.

It’s all very easy. All in all you might get $125 wrapped up in it.


The battery is a “Power Patrol By Interstate 12V 5AH F2 Battery SLA-1056”.

The charger number is “12BC0500D-1 Universal 12V 500ma Battery Charger w/clip”.

John ordered these from http://www.BatteriesAsap.com in Texas.

Here’s one thought about it

– Last Updated: Apr-15-11 11:46 PM EST –

You said you like the idea of a pump that turns itself on either periodically, or when there is water present, because eliminating the switch eliminates one failure point. I'd say that the opposite is true, and I think the setup already described is pretty good. A pump that turns on periodically would do so using high-tech electronics, and I wouldn't trust that as much as a plain old switch, nor would I be able to fix it if it failed. The more likely option, a pump that turns itself on when water is present and shuts off once the water is gone would do so using some kind of switch attached to a mechanical device. This would almost certainly be a micro-switch attached to either a float or a pressure sensor, and finding replacement parts would be an adventure, and replacing them would require disassembling the pump and probably having to thoroughly clean and seal things once you finished. That makes the idea of a simple switch you can buy at any hardware store seem a lot smarter. That's my opinion, especially after a recent unpleasant experience repairing that very device on a commercial-grade under-sink pump where I work (it's a device that allows installing a sink where providing normal gravity drainage isn't an easy option).

Good idea re-posting it
This may be the automatic pump you were thinking of: http://www.discountmarinesupplies.com/Whale_SS5212_Super_Sub_Automatic_Bilge_Pump.html

Someone posted about it over on cboats.net. I don’t think they used it. I think they just saw it and thought it was interesting. Note that it is 650 gallons per hour and not 1200.

Another option is a float switch. Atwood makes a marine one that you can buy at Wal Mart. http://www.walmart.com/ip/Attwood-Float-Switch-with-Cover/14150758?sourceid=1500000000000003260410&ci_src=14110944&ci_sku=14150758

I have not seen this one in the store. But it looks like an improvement over the ones I’ve seen. This one has the float completely covered (it appears) so things can’t foul it. I could consider one like that. Space is an issue though. If you’ve got it, that’s great. I think I’d still want a second pump on a manual switch.

cboats.net is a great place to read threads on bilge pumps. But since most folk over there already either have one or boats with someone who has one, it’s kind of hard to find a “start here” thread.

Also, Eric Nyre has also been experimenting with pumps and batteries for a long time. He is probabably using something more high tech than simple SLA batteries.

I agree with that

– Last Updated: Apr-16-11 5:39 AM EST –

If I had an automatic pump, I'd want a second on a switch.

I'll just note that the switch, if well placed, isn't a big deal to hit (at least for open boaters). And these pumps can be run dry for a fair bit. So if you enter a rapid and you want to turn it on beforehand, that's fine. I've never heard of anyone ruining a one of these pumps running it dry. I certainly don't worry about running mine dry for a full minute. You'll find that there's almost always some kind of water in there anyway. Just the stuff that continues to drain off the airbags is enough to keep a little bit of water around a well-placed pump.

bilge pumps
I have been poling whitewater boaters on their pump setups for a little while now.

I haven’t come across anyone who uses a pump with an automatic switch. Paddling whitewater, there is nearly always some water in the boat, and my guess is that an automatic switch would drain the battery more quickly and needlessly.

Although there are proponents of NiCad and Lithium ion batteries, most boaters have gone with sealed lead-acid batteries. They are cheaper, and are actually waterproof and can be used without cases, at least in fresh water. They are a bit heavier.

Here is a nice pdf describing installation of a 2 pump system: http://www.cboats.net/media/pdfs/moneypenny/dps.pdf

Here are some other recent threads discussing pumps, switches, and batteries:






Good links.

It should probably also be noted that the Atwood 1250s are no longer available and folks are using the newer 1200s.

auto switches
yeah, I’d skip on the auto switch. They’re generally float switch activated, so if your carrying your boat to the put-in…the pump would be on. The other thing is they’ll pump until the bilge is to a certain level, then stop. Once stopped, the water in the exhaust goes back to the bilge and the pump activates again, and tries to get rid of that water…I’ve drained deep cycle boat batteries dead due to this issue on my sailboat.

Gnarlydog News
I didn’t read the other thread so I don’t know if this is a repeat but… Gnarlydog has a kayak based setup with interesting switch options, and a charger I think.


More on switches
The pump I was thinking of is by Rule. They come in a variety of size and capacities. The pump turns on every 2.5 minutes and features solid state electronics that senses if there is resistance. If there is, it means there is water to be pumped, and the pump stays on. If not, the pump knows there is no water to be pumped and turns itself off. Electronics are totally sealed with no moving parts, so it should be highly reliable. These might be okay for a sea kayak, but in a ww, open boat situation, I don’t want to wait an average of 1.25 minutes and a max of 2.5 minutes for the pump to turn on. The Rule system gets good reviews on the power and sail boating sites, where people leave them hooked up for long periods of time and report their batteries are not being drained. How this works, given the tube draining issue pointed out by daggermat, I have no idea, unless maybe there is some sort of check valve (possible failure point) built into the pump.


Another option is a mirus switch made by Johnson. It, too, is a sealed piece of electric circuitry that uses “field effect detector cells producing micro-electrical fields that detect disruptions caused by water and fluids”. Again, totally sealed and no moving parts, so should be reliable. However, mounted on a vertical surface, it turns on when the water depth is 2" and turns off when the water depth is .75". I guess that’s okay, but ideally, I’d want something that turned on with less water and kept going until it removes water to the limit of the pump. These switches are not cheap: $30 - $40.


You folks with bilge pumps, what is the limit of the pump–how dry does your pump get your boat?

The sea kayak scenario that has always concerned me is being out in conditions that were bad enough that I, for some reason, had removed the skirt and had a boat full of water. I could never see myself operating a hand pump around the skirt while holding a paddle and trying to control the boat. The Rule pump would hugely improve this situation, even if the pump didn’t turn on for two minutes. But two minutes in a boat full of water trying to negotiate a rapid would be a long two minutes.

And GBguy, true enough about parts going bad. Here again, I differentiate between ww boat and sea kayak. Salt water seems especially effective at ruining electrical connections. That is, IMO, a factor that favors sealed, solid state electronics over mechanical switches and hand built electrical connections. DMatt you sail salt water, you agree?

Thanks for the pics Clarion and links pblanc, and for others’ contributions. Not sure what, when, and if I’ll do it, but wanted to share what I’d learned.


Hey Chip, early this morning I almost posted again, as I sort of regretted saying what I did in the way that I did. I regretted it because I’ve seen enough of your posts to know that surely I hadn’t said anything you hadn’t already thought of yourself. Sure enough, after reading your new post, and even as much as I like to keep things simple, the electronically controlled stuff you mentioned sounds pretty good to me. A person would just have to decide for themselves how to weigh the value of simplicity against that of high-tech, and manual control against time lags and possibly “slightly incomplete bailing”.

How much water left in boat

– Last Updated: Apr-17-11 7:47 AM EST –

Chip as long as you mount the pump so that it stays right down on the floor, it will get very dry, dryer than you can get with a bleach bottle. I have my pump mounted right in the lowest part of the boat and off center. Being off center, I can lean my boat at the end to get out the last of the water.

Each individual saddle sets up differently and you may have to get creative. The Mohawk saddles set up very nice for pump(s). My Shaman worked pretty well too (different saddle). I've got pics of that setup on another computer and I'll try to post a link to them.

With those older Atwood 1250 pumps some folks were cutting into their saddle and placing the pumps under them. Eric Nyre did this. But he said it weakens the saddle. But now that the 1250s aren't available and have been replaced with the higher profile 1200s, that option would seem more difficult to do well. Of course you could cut a tunnel in the saddle and reinforce it with some kind of rigid box. But for me that stuff is too complicated to mess with. It's not necessary in a larger WW boat. Maybe a 10 footer would require it.

Update: Pics of the pump in Shaman http://sports.webshots.com/photo/2962800300043436830smbBWX and the next one

Chip, like Clarion said. These pumps get all but the last few drops of water out of boat. I think an automatic switch is going to far. I want to be in control of the pump. We were paddling in rain and big water on the Cassellman. I had water in the boat all the time. I did not hit the switch untill I felt the wieght of the water bugging me.

Other discussions
I’m on my way - bought a Atwood Tsunami 1200 at Wal-Mart yesterday.

Here are a couple of other outfitting discussions:

http://cboats.net/cforum/viewtopic.php?t=5857&highlight= (look for the Scott R post)

For kayaks: http://www.qldseakayak.canoe.org.au/site/canoeing/qldseakayak/downloads/BILGE%20PUMP%20INSTALLATION.pdf

Rapidrunner has already built systems, but their installation guide may be a help with suggestions and ideas: http://rapidrunnerbilge.com/instructions.php

hand built switches
…“That is, IMO, a factor that favors sealed, solid state electronics over mechanical switches and hand built electrical connections. DMatt you sail salt water, you agree?”…

After 10 different sea kayaks (salt water use) with magnetic switches (http://www.flickr.com/photos/gnarlydog/2453728366/in/set-72157604806048123) and a few years of operation I have yet to see one fail.

I know that’s a small number for real statistics but so far so good. Can’t say the same for “factory” switches that are sold as waterproof.

Big virtual hug :slight_smile:
GBguy, I feel the same way about your posts and saw nothing to take offense at in what you wrote. Your posts are always worth reading. ~~Chip

What I would love to see
It should be pretty easy to design a circuit to shut off a pump when the current drops as it runs dry. I believe some of the electronics described include that.

I’d love to have a pump that started with a momentary push button and stopped 30 seconds after the pump ran dry.

Just slap the button to start it and it shuts off when it’s not needed.

So far it’s just a dream.

Not pumping yet
My birthday rolled around and family members wanted gift suggestions. They looked like deer in the headlights when I started reeling off specs from this thread for pumps, fittings, clamps, etc. “Please,” they implored, “go buy it, we’ll pay”.

What a pain in the neck. No place had everything, and I still don’t have all I need. Frustrated, I lost my normal, go cheapness, bought pricey things I thought would lead to a quick solutions.

In the sea kayak, I am going to use a Rule-Mate 750 pump, which has a built-in, field-affect water detector. It turns itself on when the water gets to 2.75" and turns itself off with 0.5" of water left in the test pail. It also has a wire for a manual switch, which I’m inclined to ignore, and just rely on the auto switch.

The Rule-mate costs a shocking $100, but the beauty is I can just wire it to a battery, connect a hose and I’m done. Using a totally sealed, gel battery, I plan to eschew the drybox. I will monitor corrosion at the terminals each time I connect it to a charger. We’ll see what happens.

Everybody else writes about fuses. The wiring diagram shows a fuse. What is the fuse protecting? We aren’t putting much in these circuits. I’ll have a battery and a pump. If the pump goes bad, what’s left to protect?

The canoe will get the Tsunami pump. West Marine lists the 1200’s for $30. First time I ever saw a price lower than at Walmart. I want a switched connection in the canoe. Don’t want to wait for 3" of water before the pump starts.

I can’t find 1-1/8 tubing. Not at Lowes. Not at West Marine. Have not checked the Depot. The thru-hull connectors I’ve identified are for power boats and have capacity to go through almost two inches of hull, so they end up being bigger than what I’d like. Has anybody found any more compact?

Frustrated to build, leads to poor shopping decisions.


Website for Electric Bilge Pump Kit

– Last Updated: May-15-14 9:48 PM EST –

To put together a canoe electric bilge pump kit, it takes 6 vendors and several hours to find the parts, assemble, and install the completed kit.

1) Electric bilge pump - Internet
2) 1 1/8" Marine bilge hose - Internet
3) Electrical components - wires, fuse holders, & wire connectors - Electrical Supply Co
4) SLA battery & charger - Internet
5) Minicell & Contact Cement - local boat outfitters
6) Plastic baseplate & bungee cords - Home Builder's Warehouse

It is difficult to select quality parts and the correct sizes on all the choices listed above to make the bilge pump kit.

Remove the guess work and hours of internet research, and buy a Solo Bilge Pump Kit from this website:


It's good to have an electric bilge pump in your canoe. Here's some reasons why:

-It saves energy not having to manually pump the water out
-Less time spent pumping water out of your boat
-More confidence to try harder lines
-It allows you to go through whitewater rapids - not skirting around the edges
-Dropping off a 4' ledge gets water in your boat - no fuss anymore
-In continuous rapids - just flip the switch and keep the fun coming
-It makes self rescue safer - by quickly jumping back in and pumping the water out in less than 2 minutes
-Peace of mind knowing that a swamped canoe no longer means maneuvering over to the river bank to dump it out
-Front & side surfing are more enjoyable since you don't get excited about water collecting in the boat
-Practicing eddy turns, peel-outs, S-turns, & backward moves are more enjoyable by spending less time bailing and more time learning
-When you roll a canoe it comes up full of water, just flip the switch for fast water removal
-No need for your skirted friends to wait in eddies while you bail your boat
-Once you install an electric pump, you'll never go back to manual bailing