We fabricated some fiberglass padeyes and installed d-rings under the deck in the hatches. A bungee will be fabricated to stretch between the d-rings to keep gear in the hatch from shifting and popping the hatch cover off.
Thigh plates were built from extra strips and glassed on both sides. Slots were created as attach points for the Immersion Research back band that will be installed once we're done with the boat. The thigh plates will also locate the seat once the fiberglass cloth retaining the thigh plate cures and is sanded.
The seat was carved from a block of 3" thick closed cell foam. It can be shaped with lots of different tools but is a messy job with black rubber dust flying everywhere. This time I shaped it with a coarse sanding disk in a 4" angle grinder while Kathy kept a vacuum hose close to suck up as much dust as possible.
The finishing touch was to glue a layer of single-sided neoprene to the seat. The smooth side was glued to the foam using 3M 90 high strength spray adhesive. The fabric side of the neoprene gives just enough grip to keep from sliding around in the seat when it is wet.