: I'm going to make a stab at sculpting my own seat out of an NRS minicell
: block to replace my Thermarest pad and hopefully alleviate numbuttosis.
: Questions: 1) My boat, a Pygmy AT17, has a V-shaped hull, but only
: slightly so amidships. Will I want to shape the bottom of the block to fit
: the hull cross-section, or just deform it?

Shape the bottom of the seat to match the hull first then carve out the seat area.

: 2) All accounts I've seen describe gluing the block to the hull--any reason
: not to just fasten it with velcro patches?

I have mine fastened with velcro and it works good. I like to pull my seat out after using it to keep the hull dry.

: 3) How critical is the precise fore-aft placement of the seat with regard to
: trim and weathercocking?

The people at pygmy could answer this best for you. You can install long peices of velcro so you can have some adjustment. One other tip I can give you is that if you plan on doing rolls and bracing you will have much better success if you don't use pygmy's back rest and install a backband type backrest. It will give you much more mobility when leaning back. Good luck with your seat. Minicell seats are very comfortable.
: Thanks as always.