The International Association of Nitrox and Technical Divers (IANTD) prepared these 40% Nitrox dive schedules in a standard structure that is familiar to divers trained in the use of traditional dive tables.The waterproof flexible dive tables that we offer are designed to accompany the diver on the dive and are easy to read underwater. They are nearly indestructible and can be rolled or folded into a compact size. The tables are printed on both sides of white waterproof fabric sheets using special flexible inks in black with blue and/or green highlighting. All sheets are { 7 in x 9 in | 17.8 cm x 22.9 cm } in size, have rounded corners and a punched hole so you can assemble several sheets into an easy-to-manage collection.