For river running you probably won’t have to raise you seat much, if at all. But if you are sitting a little low, here’s a cheap way to do it, from Welsh Kate’s blog on worldkayakblogs.com Also on the link is how to waterproof your boat, which is well worth a read.
If it has one, remove the old seat pad. This may mean pulling out the old rivets:
Trace the outline of the seat pad on to a camping mat and cut out the shape:
Once the extra padding has been cut out, tape around the rivet holes, to stop them from ripping through:
When replacing the seat pad back in the boat, the old rivets may now be too short. Instead of using the old rivet, Halfords sell packs of “Car Trim Rivets” which are slightly longer and work well for this purpose.
Put the new piece of padding under the old seat pad and use the car trim rivets to hold them both in place:
It should be possible to raise your seat by about half an inch this way – the only thing that limits it is the length of the rivets. If your boat doesn’t have a seat pad already, or you’re not too bothered about putting it back in, you could pad the seat even more by adding extra layers of the camping mat, glued together with evo-stik. Increasing your seat height will raise the centre of gravity, which may take some getting used to. Just go one layer at a time until you get the correct thickness of foam.
Cheap, easy and should only take an hour!