Every ship of the United States that is subject to this part shall have the equipment and apparatus prescribed therein inspected at least once each year by the Commission or an entity designated by the Commission. If, after such inspection, the Commission is satisfied that all relevant provisions of this chapter and the station license have been complied with, the fact shall be so certified on the station license by the Commission. The Commission shall make such additional inspections at frequent intervals as the Commission determines may be necessary to ensure compliance with the requirements of this chapter. The Commission may, upon a finding that the public interest could be served thereby—