For those in the USA, the FD1 is not FDA approved, (oxygen is a drug, US Navy Table 6a is a medical treatment table), does not meet the US National Standard ASME PVHO-1, was designed to a safety factor of only 4:1, whereas non-metallic vessels under PVHO-1 require a minimum of 6:1. (That means that 3 prototypes all need to achieve an equivalent depth of 990 feet sea water (fsw), a lot to expect of a fabric chamber. Read the report previously referenced above in this thread, to see what actually happened when the Naval Experimental Diving Unit of the US Navy tested it back in 1999. Would you put a diver in a single occupant chamber to 165 fsw, where, if anything goes wrong at that depth, one can neither leave the diver in, nor take him/her out, without very serious life threatening consequences?