46 CFR § 76.05-1 - Fire detection and alarm systems.
(a) Approved fire detection and alarm systems must be installed on the following vessels as set forth in subpart 76.27 of this part:
(1) Any vessel on an international voyage;
(3) Any vessel of 150 feet (45.72 meters) or less in length, not on an international voyage, having sleeping accommodations for 50 or more passengers. Vessels in this category are not required to have a fire detection system in the cargo spaces.
(b) The arrangements and details of the fire detection systems must be as set forth in subparts 76.25 through 76.33 of this part.