47 U.S.C. § 351 — Ship radio stations and operations

(a) Except as section 352 allows, it is illegal to do the following: (1) For a U.S. ship — other than a cargo ship under 300 gross tons — to sail the open sea outside a harbor or port, or for any U.S. or foreign ship (other than a cargo ship under 300 gross tons) to leave or try to leave a U.S. harbor for an open-sea voyage, unless the ship has a working radio station, properly installed and protected, run by one or more licensed radio officers or operators, in a way that doesn't endanger the ship or the station. This radio station must meet the size-based rules in (A) and (B) below. A U.S. ship must also carry a valid station license issued under this chapter. (A) Passenger ships of any size, and cargo ships of 1,600 gross tons or more, must have a radiotelegraph station that meets this part's requirements. (B) Cargo ships of 300 up to 1,600 gross tons must have a radiotelephone station meeting this part's requirements, unless they already have a qualifying radiotelegraph station instead. (2) For a U.S. ship of 1,600 gross tons or more to sail the open sea, or for a U.S. or foreign ship of that size to leave or try to leave a U.S. harbor for an open-sea voyage, unless the ship has efficient radio direction-finding equipment approved by the FCC, properly adjusted and in working condition. (b) A ship that isn't covered by this part when it starts a voyage doesn't become covered partway through just because bad weather or some other cause outside the control of the master, owner, or charterer forces it to deviate from its planned route.