A handheld bilge pump is far from ideal for emptying your cockpit after a self- or assisted sea kayak rescue. Pumps are slow and demand an open sprayskirt to use. Worse still, they require both hands and therefore prevent bracing and paddling--typically the top priority after re-entering a flooded cockpit in rough-water conditions. Despite these shortcomings, the majority of sea kayakers still rely on a handheld pump.
Canadian paddler James Scarrow has developed a cheap, easy to build, battery-powered bilge pump solution for his Seaward Quantum touring kayak. He purchased a compact electric bilge pump in the marine section of his local hardware store. The 12-volt pump is smaller than a can of beer and is rated at 600 gallons per minute.
He wired the pump to a standard eight-unit holder for AA batteries, purchased from an electronics surplus store (in series these 1.5-volt cells produce 12 volts). Together, eight alkaline batteries pack enough juice to empty a cockpit at least three times before the batteries start to show signs of power loss. Scarrow believes that replacing the batteries at the beginning of each season with a fresh set of brand-name batteries is a less expensive solution than attempting to use rechargeables.
The battery pack is waterproofed in a Pelican 1020 case; silicone seals around two holes drilled in the case for a pump switch and pump wires. The On/Off toggle switch is mounted in the top of the Pelican case. "I designed it so the switch is behind my seat, just beneath the sprayskirt," explains Scarrow. "I can turn it on through my skirt with my cockpit sealed."
An outlet hose runs from the pump to a through-hole in the kayak's deck, where a one-way spigot allows water to exit the boat. Mounted to a marine plywood panel (which in turn attaches to the behind-the-seat bulkhead with Velcro), the entire unit is removable for transport, weighs barely two pounds, and costs around $50 complete.
|Part Description||Best Part Source|
|Low-volume 12 volt bilge pump||Hardware Supplier: Marine Dept.|
|Pump Hose||Hardware Supplier: Marine Dept.|
|Through-Hull Fitting with One-Way Valve||Marine Supply Store|
|16 Gauge 2 Pole Wire + In-Line 2 Amp Fuse-Holder||Hardware Supplier: Automotive Dept.|
|8 Unit AA Battery Holder||Electronics Supplier|
|Single Pole Toggle Switch with Waterproof Cap||Electronics Supplier|
|Pelican 1020 Case||Outdoors/Sports Supply Store|
|Marine Plywood Panel||Marine Supply Store|
1) Waterproof caps for toggle switches are often hard to find, even at electronics surplus stores. A workaround is to plaster the toggle switch's exposed top liberally with flexible silicone after installation. Place a very small amount of grease on just the ball hinge of the toggle to prevent the silicone from jamming the free movement of the switch while ensuring good adhesion of the silicone to the rest of the exposed parts of the switch.
2) Be sure to measure the clearance requirements for the body of the switch inside the Pelican case carefully before you drill the switch hole. You only get one chance to get it right!
3) Attach the Pelican case to the wood mounting panel using construction adhesive.
4) Use Velcro to attach the panel to the back bulkhead where the lowest point in the cockpit is located. Make sure the unit is easily removable for servicing the battery pack, etc.
5) Make sure there is room for water to flow around or under the cockpit seat to reach the pump to ensure a fully evacuated cockpit.
6) Store the Pelican case lid open over the off-season, and use a small amount of silicone grease on the lid's seal at the beginning of the season to ensure a dry unit at all times.