I glued one layer of minicell foam to the therm-a-rest pad.

the minicell foam came from an ex camping matress. I think its thickness
is 10mm or so / approx' 1/2"

I glued it with contact cement.

before gluing the 2 pieces together (foam & therm-a-rest pad)
I layed 2 parallel cord along the pad, so when the seat is positioned
in the boat these cords run to the width of the boat so I can tigh them
around the side plates.

in this way the seat will remain in its place even if/when
the velcroe fails.
it was mentioned as a safety issue on sk mag sometime long ago.

the cord I used is the type that looks like a bungy cord, but it's
without rubber. I wonder what's the word that will distindt it from a
"regular" bungy cord ?

you can use this assembly foam side up or therm' side up
& play with the air inside the therm' until you get it right.

it helped me alot ! but it's still not perfect.

I'm still planning on carving a dedicated seat for my dedicated butt
when I get the time (never....)

good luck,

Erez