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Re: Review: Electric Bilge Pump for Kayaks
By:LeeG
Date: 8/13/2009, 2:23 am

: In rough seas, especially for touring kayaks, we find that it is dangerous
: and energy consuming to pump out your boat while also trying to keep
: upright. We are developing a prototype for an electric bilge pump for
: kayaks. The specs call for the unit to vacate a fully submerged kayak in
: about 4 to 5 minutes, using a DC battery. The base unit would consist of a
: pumping unit, battery and charging station for in-home and in-car.
: Optional add-ons would be a solar charging power kit, surface mounted
: on/off switch and surface mounted hose to expel the water.

: We are trying to guage what the market would be willing to pay, in order to
: see if the economics of the product would work. So two questions. 1.)
: Would a product of this type be interesting to you? Under what parameters?
: 2.) What would you be willing to pay for the base product? For the
: optional products?

: Being a fellow kayaker, who deeply loves the sport, I appreciate your
: feedback on this!

: Many thanks, LM

Landon, I think it's a great idea. If you make a good product and market it well I think you could price it around the price of a decent spare paddle or LED bike headlamp. Somewhere around $125-$150. But it has to WORK and be durable, not a variation on the Attwood WaterBuster. Ten years ago I sent them a letter saying there was a potential market for an upgraded WaterBuster for around $75 but no response.

I think the design challenge is clarifying method of operation and installation options. My preference would be a couple of options from automatic to manual to something inbetween(haven't figured that yet) with the switching mechanism free from accidental activation. I'm not a fan of external switches and wiring as you've got more routes for leaking and corrosion. Make it like any manual pump, self contained and transportable.

Your impression about pumping is absolutely correct, assisted rescues make a lot more sense than pumping out. The primo candidate for electric pumps is doubles as the odds of pumping out a double in rough conditions is about nil.

I'd look to market this pump outside of the kayaking community even if that's your intended market because a well designed portable pump for $125 is about what a manual pump would cost to install in a 30' sailboat, ie. Whale Titan. The Attwood Waterbusters sells for a reason, it's cheap and it works,,within limits. Me thinks you'll find more boat owners of all types tossing a DURABLE portable electric pump in their lockers than you will sea kayakers drilling holes in their kayaks. Have you used the Attwood Waterbuster? It works but has waterproofness limitations and breaks easily if dropped. I went through three putting 3 D cell 2v gel cells in one and 5 Nicad in another instead of the regular 3 1.5v D cell alkalines. It moved a lot more water than the stock 4.5v setup. The problem is that the switch is barely waterproof, needs to be sealed and the seal at the impeller is inadequate once the motor stops working and it draws a vacuum while cooling sucking standing water into the unit.

Like homemade versions I've seen on the 'net I'd go for a small rectangular dry box size about 3"x5"x7". I'd leave the method of mounting to the customer but the marine market should make it heavier than water so all a person has to do is tether it and toss it in a dinghy. For the kayak market you can do what Attwood does is have a removable steel plate or divers lead weight so that it can be secured to the bottom of the kayak in it's prefered spot and impervious to worst case use. My suggestion would be to leave that totally up to the paddler but at least have the design friendly to behind the seat, front of the seat, or at the feet installation with controlls/settings appropriate for all three positions.

For cost reasons I'd go for 10 AA 2650 mamphr NiMh cells instead of some gucci lithium ion battery. You could replace the batteries if needed. 12v 2.5 amp/hr should empty the boat quick enough.

One more time, market it to the marine market where there are more customers and durability is the issue. Being able to drop a portable pump into a swamped dinghy at the docks in cold weather and walk away from it will be a more common customer need than an owner of a sea kayak considering adding four more pounds on the kayak and drilling holes.

I like the Waterbuster size and shape, handle on top, inlet on bottom and outlet on one side with hose. Except make it tough. A dry box shape would work with attachment point for removable/optional weight. Look at the kind of micro switches on some electronics where the plastic only has to flex in a fraction of a mm but it takes a concerted effort to work it. Planet Bike Super flash rear tailight has a switch like that. It eliminates all the issues of thick special purpose rubber cover that can weather and tear.

Just to repeat, go into any marine hardware store and look at their pumps, check out outdoor/marine/jon boat/rv suppliers. That market is 100times bigger than sea kayaks. Don't go for a simple on/off switch. Make it like the DiNotte head lights for bicycles. User friendly, easily replaced batteries, easily installed and removed.

Then get someone in China to make it.

Messages In This Thread

Review: Electric Bilge Pump for Kayaks
LM -- 8/11/2009, 11:49 am
Re: Review: Electric Bilge Pump for Kayaks
Mike Savage -- 8/15/2009, 6:09 pm
Re: Review: Electric Bilge Pump for Kayaks
LeeG -- 8/13/2009, 2:23 am
Re: Review: Electric Bilge Pump for Kayaks
Bill Hamm -- 8/13/2009, 2:47 pm
Re: Review: Electric Bilge Pump for Kayaks
LeeG -- 8/14/2009, 2:40 am
Re: Review: Electric Bilge Pump for Kayaks
mike allen -- 8/14/2009, 2:56 am
piezo electric laminate
LeeG -- 8/14/2009, 10:56 am
Re: piezo electric laminate
Bill Hamm -- 8/14/2009, 12:31 pm
doubles and dinghies
LeeG -- 8/15/2009, 3:05 am
Re: doubles and dinghies
Bill Hamm -- 8/15/2009, 5:47 am
Re: doubles and dinghies
LeeG -- 8/15/2009, 1:51 pm
Re: piezo electric laminate
Matthew -- 8/14/2009, 2:10 pm
Re: Review: Electric Bilge Pump for Kayaks
Brian Nystrom -- 8/11/2009, 8:57 pm
Re: Review: Electric Bilge Pump for Kayaks
LM -- 8/11/2009, 9:00 pm
Re: Review: Electric Bilge Pump for Kayaks
Don Lucas -- 8/12/2009, 9:45 am
Re: Review: Electric Bilge Pump for Kayaks
bromasi -- 8/12/2009, 1:00 pm
Re: Review: Electric Bilge Pump for Kayaks
Etienne Muller -- 8/11/2009, 5:42 pm
Re: Review: Electric Bilge Pump for Kayaks
Glenn -- 8/11/2009, 7:03 pm
Re: Review: Electric Bilge Pump for Kayaks
LM -- 8/11/2009, 9:02 pm