My response was directed at domestic travel (Grand Canyon, AZ) that is non-SCUBA in nature. This is general watersports coverage 'D' and evac coverage 'C'. Obviously, if you are diving you want something that covers decompression (A) and snorkeling/diving (B).
"Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover." - Mark Twain