Start/Finish entry mats question

Anyone out there have experience using some sort of rubber mat placed on the ground and into the water for the start and finish of an open water swim? The entry point for our swim is an old boat ramp that is no longer used so is a little rough. Looking for something that will protect swimmers feet for a short start and finish. Otherwise we need to have our start and finish line in the water. I was thinking rubber anti-fatigue type mats but am finding those to be pretty expensive and commercial operations here in our little fishing town are pretty busy using their stock pile. Ideas or suggestions are greatly appreciated! Thanks, Kevin Race Director Change Your Latitude- 57* North Open Water Challenge www.changeyourlatitude.org