The Maritime Administration ("MARAD," "we," "our," or "us") is publishing this final rule implementing the new U.S. citizenship requirements set forth in the American Fisheries Act of 1998 ("AFA") for vessels of 100 feet or greater in registered length for which a fishery endorsement to the vessel's documentation is sought. The rule implements new statutory requirements of the AFA by raising the U.S. ownership and control requirements for U.S.-flag fishing vessels of 100 feet or greater in registered length that are operating in U.S. waters, by eliminating exemptions for fishing vessels that cannot meet current citizenship standards, by phasing out of operation many of the largest fishing vessels, and by establishing new criteria to be eligible to hold a preferred mortgage on vessels of 100 feet or greater with a fishery endorsement to the vessel's documentation. The regulations set out which transactions are permissible, which transactions will require prior approval, and which transactions are impermissible and, to the extent practicable, minimize disruptions to the commercial fishing industry, to the traditional financing arrangements of such industry, and to the opportunity to form fishery cooperatives. Pursuant to 5 U.S.C. 553(d)(3), this final rule will become effective immediately upon the date of publication. The immediate effective date is necessary to provide extra time before the compliance date for vessel owners and mortgagees to request letter rulings from MARAD regarding their citizenship status and potential waivers from the rule by virtue of a conflict with an international agreement or treaty.