(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 Sec. 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.