Just the usual cautions about mixing electricity & water. The quality of the wire, switches and connectors needs to be very high (this is one place where the premium charged for marine equipment is worth it). The battery needs to be of a type which will survive being capsized without spilling dangerous chemicals onto the paddler. It must not be affected by possibly prolonged immersion in fresh or salt water.

The battery will have the highest density of any equipment on board (with the possible exception of an anchor), so its mount needs to be able to handle a concentrated weight being vigorously bounced by waves, wakes, currents, impacts, etc. It needs to securely hold the battery, even when inverted.

The pump will need to be mounted so that it will be able to suck water even if the boat is at an extreme angle. The intake will need to be clog-proof even if everything inside the boat has come loose and is drifting in the flood.

That's all I know of. In the meantime, I'm not sure how low-tech our sport is. Advanced composite paddles, computer-aided-designed composite monocoque hulls, plastics & synthetics everywhere. The cheap handheld GPS receiver that I carry with me is a better navigation system than what military aircraft were using in the '70s. Quiet, yes. Low power, yes. Low tech, not really. So an electric pump fits right in.

Have fun,

Laszlo

On the low tech side....

I've owned a couple WindRider trimarans which I have installed an electric bilge for fresh water use.  Could be done the same for a yak.  I use one of those 12V power source/jumper portable batteries. Mounted in the forward compartment should keep it dry enough.  Small bilge pumps are cheap.  A switch under the deck right behind the deck beam?  Reachable from the water.  Run wire underneath a strip of glass? 

I think it is a good idea for a flooded cockpit.  Should be an easy afternoon project and not expensive.  The 12V source would also have multiple uses.    I think I have an old bilge pump laying around.  I think I'll test it.

One thing to think about.  It is only good for a flooded cockpit.  How often do you capsize?  It would make it easier for re entry training if one, like me, can't roll. 

Kim

Waterproofing isn't really that difficult as long as you don't need to have a large depth capability.  Assuming maybe 15 feet is the furthest depth you're going to get a kayak and actually recover it (if you do a cleopatra's needle or something similar) it shouldn't be too difficult to find fairly low cost equipment designed to withstand those pressures.  I was thinking something like an outdoor fountain pump converted to dc power (or if you can find one already wired for dc) would be a perfect choice. 

To be sure you could embed the wiring in epoxy (assuming you don't want to remove it ever) or just some silicone.  Similarly the battery could be housed in a box and strapped down fairly easily.

FrankP

Well by golly I had the parts and tested it.  Filled my Duck 12 with 4" of water.  Remember the Duck has no forward compartment so this is a good bit of water. Sat it on level ground.  Emptied it in under 3 min.   Down to 3/8" of water.  Keep your sponge.  A little leaning got me down to the 3/8" mark.  Faster than a hand pump by far.  Can be pumping while re entry is being made. 

I used an Attwood v500.  I see it is listed at $30.  I chose this pump because I inherited it somewhere over the years.  I think it would make an excellent choice.  My power source is a bit bulky for a yak.   A thru hull fitting could be placed where re entry is not made for the discharge.

On the Duck I would mount the pump  behind my seat.  Battery in the aft compartment.  Switch behind the deck beam. 

I made the comment earlier on 'How often would it be used?" Somebody slap me.  Used once in an emergency could make it the best thing you ever did. 

This is a fantastic idea. 

Looking at the picture of the pump there is an important detail: Fuse 2Amp.

I fly gliders and we have similar issues (less the water) when it comes to electrics in our craft and of course, now that you have a battery, why stop @ a mere pump?  Nav lights, power for the GPS, radio, compass light, coffee maker....

Couple things that you should include:  Master Switch close as possible to the battery.  The gel cell batteries are a popular choice in the aviation world, no acid to melt through stuff, good cycle life, reasonable price, good weight to power ratio and of course rechargable.  Fuse the battery.  Put this on the leads that are attached to the battery so that even when you have the battery out you have fuse protection.  A friend had his wires melt while carrying the battery when the zipper on his coat shorted the exposed end of the connecting wire.  On that note, assuming you have soldered a short wire/connector, tape up your joints on the battery.  Another friend lost his glider and trailer when the battery stored in the trailer shorted and caught fire.

I love the idea and will be thinking about it when my wood duck starts to hatch.

Batteries: http://www.wingsandwheels.com/page24.htm

Wordsmith here again.   Thanks for the supportive and interested comments, guys - I was half expecting to have buckets of derision heaped upon me! (and I do agree with Laszlo that maybe we are not all that lo-tech, especially in the materials area)!  

Since my first post on this I've found a couple of very detailed articles by a member of the Queensland Sea Kayak Association here in Oz (Queensland being on the east or Pacific coast of Australia - we are about halfway up the east coast).   One of the articles describes how he designed and made a completely waterproof magnetic switch - very ingenious!  

The pump he illustrates is a RULE brand item and looks near-identical to the one that Mr Kim illustrated.   My local kayak shop can source one for me for $35, so they are quite affordable.   The shop owner there also told me that he knows of people installing using this sort of pump who simply utilise a 12V rechargable battery from a cordless drill or similar device - they are probably made to be pretty reliable and robust, even the cheaper brands. 

I'm trying to get in touch with this guy to have a look at his installation and learn more - if successful I'll post further details here.

Meantime, you may like to take a look:

Go to <qldseakayak.canoe.org.au> 

Along the second (blue) line click on <Resources>

Click on <Club Member's Articles>

Open 2 x articles by Damiano Visocnik: (1) Bilge Pump Installation and (2)Magnetic Switch.

Enjoy - and again thanks for inputs.   I am seriously interested in this concept for the next craft!

Wordsmith

Foot brace mounting kit for mounting the pump?  Use two mounts for the pump and the other two for the battery mount?

I have an electric pump in my kayak. It is powered by a 12V rechargeable battery and is mounted in a wterproof day hatch with a switch in the cockpit.  In the event of a roll, particualrly if you come out of the boat you simply get back in and press the switch. I am not sure what the specs are but that pump can really move that water.

There is a jet on deck at the rear of the cockpit and it shoots the water twoards the stern.  Works like a charm.     

Frank - Pictures?

Do a GOOGLE search for Electric Bilge Pump Kayak.

You can find lots of ideas, battery powered, solar powered, how-to's where all the electronics fit in a pelican case.

DM

No worries Dave. I will post some pictures. It was fitted by a mate who I paddle with and he bought about 6 pumps and batteries and did our whole group. 

He has made a SS braket to hold the battery in the rear compartment on the bulkhead behind the cockpit, or in the case of my boat in the day hatch compartment.     

Thanks for the leads on the rudder.  My kids have grown up, left home  and taken all their vehicles with them. I need to fill up the empty spaces in my garage with a couple of kayaks under construction. I am doing a CLC and my mate is doing something else, but he is yet to make a decision.

I hope to install this weekend.  I went to Cabella's and ordered a battery. 

$38 for that.  I will use my old pump which can be replaced for about $20.  I have to make a trip to West Marine for a water proof toggle switch.  That will cost $23. 

Kim

As the initiator of this thread, and encouraged by other posts, I've been following this up quite vigourously.  

I looked at batteries such as Kim has illustrated above, but found them quite bulky and heavy - several pounds at least.   The cost here was comparable to Kim's item at around $30 without the charger.   I now intend, after a bit of experimenting, to use the 12V rechargeable battery from one of my cordless electric drills.   It's very robust and carries a good charge for its intended heavy-duty drilling use, so it should be ideal for driving the pump.   It is also very light at only 400 grams, or < one (1) pound in your US money.   I intend to remove the battery from the craft after every outing so as to be able to still use the drill and to ensure it's always charged - although I hope that pumping activity will be minimal!  

Proper waterproof cases as used by photographers are quite expensive at about $35 for the size needed ('Pelican' brand), so I'll mount the battery inside 2 x good quality waterproof 'Tupperware' type plastic containers, one inside the other for optimal waterproofing.   Two full cycles in the dishwasher have proved their watertight qualities quite adequately!  

The battery will be well padded with stiff foam inside its container, and that one well padded inside the larger outer container.   This will then be strongly secured by a nylon strap on the hull bottom in an epoxied-in ply 'frame' immediately behind the bulkhead so as to keep wiring to the switch and pump to the shortest length possible.

The pump (about $25, 'Johnson' brand, made in US, pumps 450 US gallons/ hour) weighs only a few ounces, and has the minor benefit of a built-in bracket which will allow it to be screwed onto the aft cockpit bulkhead behind the seat, nice and secure.   It's very compact, too - only 4" tall and 4-1/2" diameter at the base, about the size of a small cup or mug.   An alternative 'Rule' brand item, also US-made, is even smaller at 3-1/2" x 2-1/4", and a 500 gph unit costs about $38 here.  

A waterproof switch is very cheap at about $2.40 from our Oz equivalent of Radio Shack or Tandy, but if necessary I'll waterproof it further by putting a rubber finger-stall over it, nice and tight.   An alternative would be an automatic float switch, at about $37 ('Johnson' brand again).   All up, with PVC hose, through-deck hose outlet, switch, wiring, I reckon on no more than two (2) pounds of added weight and a total cost of under $40 using the cheaper options above.

For me, this will bring the feeling of a little added security 'out there' and the joys of fiddling and doing something a bit different!   I'm not going to retro-fit this to the Ches 17LT, but it will be built-in to the new Shearwater 17 when construction starts soon.

An interesting challenge - thanks to all for input and ideas...keep on reprting.

Cheers...

Wordsmith

  I have a (non-expert) concern about overheating of the battery.  I hope that only a small portion of the surface of the battery will be covered in foam?

I know only this: that a battery puts out some heat whilst driving current, and that foam can be awfully good at trapping heat.

Thanks for the heads-up on this point, Camper.   The battery won't be completely covered in foam, just wedged-in with short stiff lengths on each of the four sides, and the same with the second (outer) container as a means of holding the smaller container (with battery) inside it.   Plenty of air inside both, although clearly not circulating.   It's a good point and I'll certainly do a test-run or two before finalising things!   As I said above, I hope the pump doesn't have too much use anyway....

Cheers...

Wordsmith

Wordsmith, I live on the Sunshine Coast and have a pump fitted to my Sea Bear. I have promised Dave some photos so maybe hold your fire until you see them. I think you are over engineering this problem.

I do have a waterproof day hatch on my boat and the battery is ftted there. There are no issues with waterproofing. If you put the battery in the rear compartment then it should be OK if the compartment is waterproof.

My pump was fitted by a mate who does this sort of thing for a living. He has used fairly basic components and the whole thing works perfectly.  I have filled the cockpit with water and the pump has pumped it out easily. I have a nozzle facing to the stern which directs the water away from the cocpit with some force and provides a very neat finish as you will see in my pics.  By the way, the battery heating up is not an issue.   

What is the amp rating on your batteries?

Thanks

Kim