My Pescador seat also sucked. A neighbor gave me a boat seat for my skiff. It had 1-1/2" open cell foam in the bottom, which sucked. I replaced it with closed cell foam. Much improved.
I took the Pescador seat out, cut the open cell foam to fit around the seat fasteners, then put the seat back in. What a difference! I can go out for hours without my butt hurting. The seat back still leaves a lot to be desired, but my free fix worked. I've seen China seats online as low as $40.
I'm an Eighth Day Adventist. On the Eighth Day, God went fishing!