I have made several of these for boats. I have an S6. Think of it as a work in progress. I get a cell foam block and get a general idea how its going to fit and draw out the lines on the foam based on the nose of the boat and how you want your feet (lotus, flexed, etc.) Think about shaping it in the nose how the boat is shaped. You will end up making concave divits and a better bulkhead.
You want to start with too much on the section closer to your feet, so you can cut and shave. It takes a lot of, putting in the block, getting in the boat, taking out of the boat, shaving, repeat. When you get a pretty good fit. Stuff it in, go paddle. No glue yet.
After you have that good fit, you can glue it in (3M adhesive). You want enough glue if you swim it won;t go anywhere. Stuffing it in may work on the short term, but eventualy will come out if you swim.
The tools I use:
- Old long skinny serated bread knife, w/blunt tip -allows for long cuts, you could use an old steak knife too. The serated edge helps.
- Dry wall plane (for shaving the foam)
- Sharpie Marker
- 3M super 777
- Tape measure
- A cheap six pack
- Gloves and mask for the 777 -that sh#t is sticky!