(a) is of sufficient size to accommodate all submerged divers,

(b) provides adequate emergency breathing mixture for the safe decompression of divers in an emergency,

(c) contains adequate equipment, protected against inadvertent operation, for supplying the appropriate breathing mixture to persons occupying or working from the chamber,

(d) is equipped with a voice communication system whereby conversation may be maintained with persons at the diving station, with surface supervisory personnel and with divers outside the chamber,

(e) contains equipment for lighting,

(f) contains first-aid equipment that meets the requirements of section 12 and lifting equipment sufficient to enable an unconscious or injured diver to be hoisted into the chamber by a person located in the chamber,

(g) contains a stretcher and blankets,

(h) is used in association with lifting gear that enables the chamber to be lowered to the depth at which the diving operations are to be carried out without excessive lateral, vertical or rotational movement taking place,

(i) is provided with a means whereby in the event of a failure of the main lifting gear, the chamber can be returned to the surface, and

(j) limits the diver’s umbilical to 30 m.