I've got my foam for making my island and have it laid out on saw horses but haven't cut into it yet. When I make my cuts I want to be sure I can make some of it look natural and perhaps like rock. I made a foam cutter by placing electric fence wire between two alligator clips of a battery charger but I may just use a sharp fillet knife. I bought a bag of growing medium that expands to 4 cubic yards for my plants. I've been afraid to start cutting because I can't visualize just exactly what I want and how it will look. But if it looks like hell at least it will still float I hope. I'll take some pictures as I go along and we will see what happens.