Over the course of several extended trips, my expensive fiberglass cooler sustained significant damage from block ice bouncing around inside. Stress cracks at the inside edges turned into broken gelcoat, and then damage down to the foam core. To prevent this, I bought a rubberized bathmat (the type with suction cups on the bottom) and trimmed the sides, leaving some excess on the front and back. I placed it in the bottom, and now my block ice rides in a cushioned cooler. The mat hoses off easily when you come off the water, and it also works great for floor compartments and anchor lockers.