33 CFR 104.245: Communications.

(a) The Vessel Security Officer must have a means to effectively notify vessel personnel of changes in security conditions on board the vessel.

(b) Communications systems and procedures must allow effective and continuous communication between the vessel security personnel, facilities interfacing with the vessel, vessels interfacing with the vessel, and national or local authorities with security responsibilities.

(c) Communication systems and procedures must enable vessel personnel to notify, in a timely manner, shore side authorities or other vessels of a security threat or incident on board.