29 CFR §1910.422

1. (a)General. The employer shall comply with the following requirements which are applicable to each diving operation unless otherwise specified.
2. (b)Water entry and exit.
   1. (1)A means capable of supporting the diver shall be provided for entering and exiting the water.
   2. (2)The means provided for exiting the water shall extend below the water surface.
   3. (3)A means shall be provided to assist an injured diver from the water or into a bell.
3. (c)Communications.
   1. (1)An operational two-way voice communication system shall be used between:
      1. (i)Each surface-supplied air or mixed-gas diver and a dive team member at the dive location or bell (when provided or required); and
      2. (ii)The bell and the dive location.
   2. (2)An operational, two-way communication system shall be available at the dive location to obtain emergency assistance.
4. (d)Decompression tables. Decompression, repetitive, and no-decompression tables (as appropriate) shall be at the dive location.
5. (e)Dive profiles. A depth-time profile, including when appropriate any breathing gas changes, shall be maintained for each diver during the dive including decompression.
6. (f)Hand-held power tools and equipment.
   1. (1)Hand-held electrical tools and equipment shall be de-energized before being placed into or retrieved from the water.
   2. (2)Hand-held power tools shall not be supplied with power from the dive location until requested by the diver.
7. (g)Welding and burning.
   1. (1)A current supply switch to interrupt the current flow to the welding or burning electrode shall be:
      1. (i)Tended by a dive team member in voice communication with the diver performing the welding or burning; and
      2. (ii)Kept in the open position except when the diver is welding or burning.
   2. (2)The welding machine frame shall be grounded.
   3. (3)Welding and burning cables, electrode holders, and connections shall be capable of carrying the maximum current required by the work, and shall be properly insulated.
   4. (4)Insulated gloves shall be provided to divers performing welding and burning operations.
   5. (5)Prior to welding or burning on closed compartments, structures or pipes, which contain a flammable vapor or in which a flammable vapor may be generated by the work, they shall be vented, flooded, or purged with a mixture of gases which will not support combustion.
8. (h)Explosives.
   1. (1)Employers shall transport, store, and use explosives in accordance with this section and the applicable provisions of §§ 1910.109 and 1926.912 of Title 29 of the Code of Federal Regulations.
   2. (2)Electrical continuity of explosive circuits shall not be tested until the diver is out of the water.
   3. (3)Explosives shall not be detonated while the diver is in the water.
      1. (i)Termination of dive. The working interval of a dive shall be terminated when:
         1. (1)A diver requests termination;
         2. (2)A diver fails to respond correctly to communications or signals from a dive team member;
         3. (3)Communications are lost and can not be quickly re-established between the diver and a dive team member at the dive location, and between the designated person-in-charge and the person controlling the vessel in liveboating operations; or
         4. (4)A diver begins to use diver-carried reserve breathing gas or the dive-location reserve breathing gas.