 NOAA has used rather different saturation decompression schedules for relatively shallow (less than 100 fsw) air and nitrox saturation dives, which use oxygen breathing when pressure is reduced to less than 55 fsw.The divers use surface supplied umbilical diving equipment, utilizing deep diving breathing gas, such as helium and oxygen mixtures, stored in large capacity, high pressure cylinders.The gas supplies are plumbed to the control room, where they are routed to supply the system components.