; or (B) equivalent to 51 percent of such vessel’s total carrying capacity of 20-foot equivalent units before calling on a foreign port. (b) Requirement The owner, operator, or agent of a vessel to be provided preference pursuant to paragraphs (2) and (3) of subsection (a) shall inform the respective covered port authority or marine terminal operator, as applicable, in writing not less than 7 days before the date on which the vessel calls on the port expected to provide such preference. (c) Filing certifications Ocean common carriers shall file with the Federal Maritime Commission any certifications under subsection (a) to a covered port authority or marine terminal operators not less frequently than each calendar year. (d) Authority To collect data (1) In general Each covered port authority or marine terminal operator, as applicable, shall submit to the Director of the Bureau of Transportation Statistics such data as the Director determines to be necessary for the implementation of this subsection, subject to subchapter III of chapter 35 of title 44. (2) Publication Not less frequently than once each fiscal year, the Director shall publish statistics relating to the vessels provided preference pursuant to paragraphs (2) and (3) of subsection (a), including— (A) the total number of vessels by registry, class, and type; and (B) the average percentage of cargo bookings of U.S. exports reported (by the ocean common carrier) pursuant to paragraph (3) of subsection (a) identified by the— (i) average percentage of all such vessels’ total carrying capacity by tonnage; and (ii) the average percentage of all such vessels’ total carrying capacity of 20-foot equivalent units. (e) Rules of construction Nothing in this section shall be construed to— (1) preclude a port authority, marine terminal operator, or vessel from following a direction by the Coast Guard or from the Vessel Traffic Service maintained under subchapter I of chapter 700