46 C.F.R. § 197.432 Surface-supplied air diving.
Title 46 - Shipping
The diving supervisor shall insure that— (a) Surface-supplied air diving is conducted at depths less than 190 fsw, except that dives with bottom times of 30 minutes or less may be conducted to depths of 220 fsw; (b) Each diving operation has a primary breathing gas supply; (c) Each diver is continuously tended while in the water; (d) When a diver is in a physically confining space, another diver is stationed at the underwater point of entry and is line-tending the diver; (e) For dives deeper than 130 fsw or outside the no-decompression limits— (1) Each diving operation has a secondary breathing gas supply; (2) A decompression chamber is ready for use at the dive location; (3) A diving stage is used except when a bell is provided; (4) A bell is used for dives with an in-water decompression time greater than 120 minutes, except when the diver is using a heavy-weight diving outfit or is diving in a physically confining space; (5) A separate dive team member tends each diver in the water; (6) A standby diver is available while a diver is in the water; and (7) Each diver has a diver-carried reserve breathing gas supply except when using a heavy-weight diving outfit or when diving in a physically confining space; and (f) The surface-supplied air diver has the equipment required by §197.346 (b) or (d).
Title 46: Shipping
PART 197—GENERAL PROVISIONS
Subpart B—Commercial Diving Operations
specific diving mode procedures
§ 197.432 Surface-supplied air diving.
