Quietman's Custom Kayak Seat Cushion
Almost everyone who puts in long sessions of four hours or more will need some kind of supplemental padding for the kayak seat. There are several nice ones you can find for sale on line or in kayak stores, as well as many that are for other uses that work great also. Some are pretty expensive and none are custom fitted to your kayak and your rear end!
Here is a simple and CHEAP way to make a great pad, one that will not get a hole in it and deflate, and can be made as thick or thin as you "feel" the need for. It also can be cleverly designed by yourself to channel water away from your rear end and out the scuppers instead. You may not realize it, but some kayak designs have a seat scupper or scuppers that tend to act like an icy saltwater Bide when there is chop or swell.
Go to Wal-Mart or a similar store and look in the camping department. You will find rolled up closed-cell (non-absorbent) ground pads for about $5.88. Buy one of these and take it home. There put your seat in your yak and determine if your seat needs help with drainage or not. Once you decide, you can then pull the seat and lay a sheet of newspaper or poster board in the seat pan, and trace out the shape you think is best for a pad.
Cut out the paper, trace this to the foam, and cut it out with scissors. It is super easy and fast to do. If you want a thicker pad, make more layers. If you want to make a drainage channel, cut out the bottom layers of foam with the channels, and then glue them to the upper layer (s) with 3M 77 contact adhesive spray or contact cement. You can build up "deflector channels" which drain the seat and force unwelcome upwelling out to the foot well scuppers instead of, well you know.
Some kayaks have NO seat drain, and in this case you can make a couple vertical scallops along the edges, and a bottom piece that channels the collected water out the front, and then stack the other layers high enough to get you out of the seat puddle. Some kayaks also have a sunken seat that can cut off the circulation under the thighs, and you can again build up the padding to relieve this while still having functional seat scuppers.
The possibilities should be obvious once you give it a try...
Quietman