312.19. Free-swimming scuba diving: If a diver’s lifeline could get stuck or tangled, the diving supervisor, when another work method cannot be used, may authorize free-swimming scuba diving, on the condition that an accompanying diver secured to the surface by a lifeline goes underwater and maintains permanent visual contact with the free-swimming diver. The accompanying diver is added to the dive team referred to in section 312.7.
If the lifeline of the accompanying diver could also get stuck or tangled, the diving supervisor may authorize the 2 divers to buddy dive in accordance with section 312.20.