If operated in an area within the coverage of an INMARSAT maritime mobile geostationary satellite in which continuous alerting is available, an INMARSAT B, C, or M ship earth station, or an INMARSAT A ship earth station if installed prior to February 12, 2004. (iv) Be equipped with a reserve power supply meeting the requirements of §§ 80.917(b), 80.919 and 80.921, and capable of powering the single sideband radiotelephone or the ship earth station (including associated peripheral equipment) required by paragraph (a)(3)(iii) of this section, including the navigation receiver referred to in § 80.905(a)(5); (v) Be equipped with a NAVTEX receiver conforming to the following performance standards: IMO Resolution A.525(13) and ITU-R Recommendation 540; (vi) Be equipped with a Category I