Section 1910.421 - Pre-dive procedures(a)General. The employer shall comply with the following requirements prior to each diving operation, unless otherwise specified.(b)Emergency aid. A list shall be kept at the dive location of the telephone or call numbers of the following:(1) An operational decompression chamber (if not at the dive location);(2) Accessible hospitals;(3) Available physicians;(4) Available means of transportation; and(5) The nearest U.S. Coast Guard Rescue Coordination Center.(c)First aid supplies.(1) A first aid kit appropriate for the diving operation and approved by a physician shall be available at the dive location.(2) When used in a decompression chamber or bell, the first aid kit shall be suitable for use under hyperbaric conditions.(3) In addition to any other first aid supplies, an American Red Cross standard first aid handbook or equivalent, and a bag-type manual resuscitator with transparent mask and tubing shall be available at the dive location.(d)Planning and assessment. Planning of a diving operation shall include an assessment of the safety and health aspects of the following:(2) Surface and underwater conditions and hazards;(3) Breathing gas supply (including reserves);(5) Diving equipment and systems;(6) Dive team assignments and physical fitness of dive team members (including any impairment known to the employer);(7) Repetitive dive designation or residual inert gas status of dive team members;(8) Decompression and treatment procedures (including altitude corrections); and(9) Emergency procedures.(e)Hazardous activities. To minimize hazards to the dive team, diving operations shall be coordinated with other activities in the vicinity which are likely to interfere with the diving operation.(f)Employee briefing.(1) Dive team members shall be briefed on:(i) The tasks to be undertaken;(ii) Safety procedures for the diving mode;(iii) Any unusual hazards or environmental conditions likely to affect the safety of the diving operation; and(iv) Any modifications to operating procedures necessitated by the specific diving operation.(2) Prior to making individual dive team member assignments, the employer shall inquire into the dive team member's current state of physical fitness, and indicate to the dive team member the procedure for reporting physical problems or adverse physiological effects during and after the dive.(g)Equipment inspection. The breathing gas supply system including reserve breathing gas supplies, masks, helmets, thermal protection, and bell handling mechanism (when appropriate) shall be inspected prior to each dive.(h)Warning signal. When diving from surfaces other than vessels in areas capable of supporting marine traffic, a rigid replica of the international code flag "A" at least one meter in height shall be displayed at the dive location in a manner which allows all-round visibility, and shall be illuminated during night diving operations.42 FR 37668, July 22, 1977, as amended at 47 FR 14706, Apr. 6, 1982; 54 FR 24334, June 7, 1989