Buy a 8' x 4' sheet of foam (about 2" thick) at Home Depot (the rigid pink stuff to insulate building walls). Also pick up some rubber flooring- heavy, dense stuff. They sell the rubber in individual sheets for a buck or two a piece, something like 15" squares that are about ¼" thick. Cut the foam to fit (typically 1 vertical piece and 2 horizontal pieces that are going along the bulkhead [for each side of the bulk head], and one piece [doubled up] oriented flat against your feet), then cover the last piece with the black flooring to give it some strength/distribute the pressure from your feet.
I've done this to a couple of boats. Makes the boat lighter, and also helps protect ankles when you smash the nose. I pull out the stock foot system and replace it with this instead.
If you're around Denver, I've got plenty of the foam left from the last time I did it you're welcome to use. PM me if you want some pictures as well.