46 CFR § 109.201
Steering gear, whistles, general alarm, and means of communication
April 15, 2021
The master or person in charge shall ensure that—
(a) Steering gear, whistles, general alarm bells, and means of communication between the bridge or control room and the engine room on self propelled units are inspected and tested—
(1) Within 12 hours before getting under way; and
(2) At least once each week if under way or on station; and
(b) Whistles and general alarm bells on all other units are inspected examined and tested at least once each week.