Communications system.

(a) Each OSV must have a communications system to immediately summon a crew member to the machinery space wherever one of the alarms required by § 130.460 of this subpart is activated. (b) The communications system must be either— (1) An alarm that— (i) Is dedicated for this purpose; (ii) Sounds in the crew accommodations and the normally manned spaces; and (iii) Is operable from the pilothouse; or (2) A telephone operated from the pilothouse that reaches the master's stateroom, engineer's stateroom, engine room, and crew accommodations that either— (i) Is a sound-powered telephone; or (ii) Gets its power from the emergency switchboard or from an independent battery continuously charged by its own charger.