If you work as an employee within the United States on or in connection with (as explained in Sec. 404.1004(b)(8)) a vessel or aircraft that is not an American vessel (as defined in Sec. 404.1004(b)(3)) or American aircraft (as defined in Sec. 404.1004(b)(2)), your work is excluded from employment if--
(a) You are not a citizen of the United States or your employer is not an American employer (as defined in Sec. 404.1004(b)(1)); and
(b) You are employed on and in connection with (as explained in Sec. 404.1004(b)(7)) the vessel or aircraft when outside the United States.