Steve,
That's not how the Indians do it, the fillet is cut with the skin on. The skin side goes against the plank / board whatever, and is tied in place with string. The board is stuck in the ground at a 5-10º angle with the exposed meat side toward the fire, it's not that hot, and it smoke, cooks for a few hours. When it's done, the board is pulled up, the string is cut and the fish removed from the board. The fish is served skin side down and the meat is peeled or cut away from the skin as you eat it. Normally this is done with nothing but a knife and your fingers. And yep they smell pretty ripe afterwords.