Thanks Kent,
Probably saved me a lot of unnecessary work. I've never had hip pads and was planning on installing them in my current Mystery project. Now I'll probably leave them out.
I can see the attraction they have, snug fit in the kayak, all cozy, if they had little pictures of kittens on them....

I agree with you, I like knee pads, but they're still an open design problem. I like to pump my legs when I paddle, twist (rotating seat). I'm going to add foot straps to my full foot-braces, which should help a lot.
The open design problem is how can I pump my knees up and down, but then lock into knee pads as quickly as possible?
Currently a knee brace for me is usually takes 2-3 movements, knee down, out, up into pad.

The ideal solution for a low stability 'yak might be a seat belt. One on the seat or maybe on each knee.
I keep coming to the idea of a seat belt ratchet connected to each knee. A fast bracing move locks it-like a seat belt does with a sudden move. Instant bracing.

Will