I recently finished building a Pax 19.5. The problem that I am having is that my feet and legs begin to go numb after 15 min of paddling. I formed a seat bottom out of closed cell foam and used the rapid pulse back band. This is the first performance boat I have paddle. Before this boat I was paddling a Dagger Blackwater single and double. Lots of cockpit room and stability with a high seat back. No numbness paddling the Blackwater. On the Pax, I've adjusted foot pegs, back band, tried support under my legs. No change in numbness. I'm 5'10" and 170 lbs. I'm thinking of purschasing a new seat with a higher back. Any suggestions on seats that I should look at? I have about 15" of room btw the hip braces. If anyone has suggestions of things I should try to elliminate the numbness I would certainly appreciate it. Thanks.