47 CFR § 80.277 - Ship Security Alert System (SSAS).
(a) Vessels equipped with a Ship Security Alert System pursuant to the Safety Convention or 33 CFR 101.310 may utilize:
(1) Equipment that complies with RTCM 11020 (incorporated by reference, § 80.7); or
(2) INMARSAT D + equipment; or
(3) Equipment that complies with the technical specifications found in this subpart.