Over the years, the OSD has noticed that there is an awful lot of water just beyond the thin skin of his kayak, some of which creeps under his spray deck and joins him in the cockpit when given half a chance.
This is generally due to breaking waves, either in surf or rough conditions. In either case, it is a good thing to have some way to remove the offending moisture before it accumulates to the point where the kayak becomes unmanageable. Now, the OSD reasons, if things are bad enough for water to get in, he wants to have both hands available for bracing, and definitely DOES NOT want to remove his spray deck. These two considerations rule out deck mounted pumps, el cheapo portable bilge pumps, bailing buckets and sponges. (More about these items later.)
The OSD has arrived at the conclusion that the best solution is a non-electric, diaphragm-type bilge pump mounted on the forward bulkhead. The pump is operated by foot pressure and can clear a completely flooded cockpit after a re-entry and roll in about three minutes. The OSD can brace and paddle vigorously while pumping. Since the pump’s outlet is in the centerline of the deck, the ensuing spout of water is entertaining and decorative, as well as being useful.
Some bulkhead-mount pump enthusiasts insist on putting a spring inside the diaphragm for return, but the OSD spurns such hi-tech and expensive options in favour of a simple length of bungee cord and the inevitable olive cleat. (See figure 1.) Not only is an internal spring an engineering challenge, but the pump is less efficient due to more limited movement of the diaphragm.
The OSD mounts the pump high enough so that the outlet pokes through the deck, without the need for additional tubing. For the suction end, he runs a length of white PVC tubing to the low point of the hull. He puts a cap on the tubing and drills a number of small holes in the bottom of the tube near the end to pick up the water. The holes must be small enough to pass the scrutiny of Dave Winkworth, who is convinced that hordes of mangrove twigs are just waiting for the chance to plug the unsuspecting orifices. The cost for this type of pumping system is relatively cheap: $45 for a Taiwanese Hand Bilge Pump and $5 for the rest of the bits and pieces. (A word of warning–the pins eventually work out of the pivot points. The OSD replaces his with stainless bolts and nyloc nuts.)
Although the OSD (being a Luddite) shakes his beard in disgust at the thought, there is a more technological way to pump water out of a kayak. This involves electricity. The OSD sneeringly points out that electricity goes Phut when in contact with sea water and that batteries get flat. However, many kayaks, notably Mirages, are equipped with electric bilge pumps which seem to work admirably. These pumps are mounted in the hull, generally behind the seat. The battery is in a separate waterproof box. Another option is to make a portable, self contained unit, with pump, battery, switch, and outlet hose. Commercial operators use this rig to empty the cockpits of swamped doubles, and the batteries seem to last a long time before requiring recharging. Cost for the electric route is: $25 – $35 for a 400 to 500 Gallon per Hour pump, $39 for a 7 ampere hour, 12 volt, sealed, lead acid, deep cycle battery and $7 for a waterproof switch.
There is another electric pump which the OSD finds akin to perpetual motion or anti gravity. This one is powered by 3 “D” cells (flashlight batteries, the round ones.) It is waterproof and can sit behind the seat. The manufacturer, Atwood, claims that it will pump 200 GPH for 5 hours before the batteries go flat. (!) When the steel base plate is removed, the rest of the unit will float. Price: $106.
At the very least, the OSD recommends that all sea kayaks carry a bailing bucket or scoop and a sponge. Buying sponges (which seem to regularly disappear) can be expensive. The OSD keeps an eye out for old foam mattresses on rubbish heaps. He cuts the foam into blocks for roof-rack padding and sponges. The bailing bucket can simply be a 2 litre icecream dish. A better device is the traditional bailing scoop. This can be made from a plastic container (a 5 litre oil container is excellent) cut so that the handle remains for gripping. (Figure 2) It is a good idea to secure the scoop and the sponge to the kayak with a light line. (String, to you, Fishkiller.)
Another option is the $25-$35 portable bilge pump, a tube-type pump which requires two hands to use. It is better than nothing, but only just.
Of course, it is best to keep the ocean outside the kayak in the first place through maintaining equipment and developing bracing and rolling skills. The OSD observes that nothing lets in more water than a wet exit.