Port and Maritime Security Act of 2000 - Directs the Commandant of the Coast Guard, in cooperation with the Maritime Administration and the U.S. Customs Service, to establish a Port Security Task Force to: (1) coordinate programs to enhance the security and safety of U.S. seaports; (2) coordinate the security operations of local seaport security committees; (3) develop standards and procedures for the conduct and triennial review and revision, if necessary, of seaport security threat assessments for U.S. seaports, including collection, maintenance, and dissemination of seaport infrastructure and overt-security equipment maps and charts; and (4) develop voluntary minimum security guidelines, linked to the U.S. Coast Guard Captain-of-the-Port controls for maritime trade, which include a model seaport concept and a set of recommended best practices guidelines for the use of maritime terminal operators. Authorizes appropriations.

(Sec. 6) Amends the Merchant Marine Act, 1936 to authorize the Secretary of Transportation to guarantee loans for seaport security infrastructure improvements at any U.S. seaport involved in international trade. Authorizes appropriations.

(Sec. 7) Requires the U.S. Customs Service to establish a competitive matching grant program for half the cost of developing technology to enhance security at U.S. seaports. Authorizes appropriations.

(Sec. 8) Amends the International Maritime and Post Security Act to require the Secretary to report annually on maritime security and terrorism.

(Sec. 9) Requires the Secretary, acting through the Maritime Administration, to publish a revised version of the "Port Security: A National Planning Guide" and make it available on the Internet.

(Sec. 10) Directs the U.S. Coast Guard to establish seaport security committees to: (1) utilize the information made available under this Act; (2) implement port security threat assessments; and (3) implement security guidelines. Authorizes appropriations.

(Sec. 11) Directs the Attorney General to coordinate the collection of port-related crime data. Authorizes appropriations.

(Sec. 12) Directs the Secretary of the Treasury, the Secretary of Agriculture, the Secretary of Transportation, and the Attorney General to work with each other, the Task Force, and the States to establish shared dockside inspection facilities at U.S. seaports for Federal and State agencies. Authorizes appropriations.

(Sec. 13) Directs the U.S. Customs Service to: (1) require all ocean manifests to be transmitted to the Service in electronic form in sufficient time for its effective use; (2) require all entries of goods, including in-bond entries, to provide to the Service the same information required for entries of goods released into U.S. commerce before the goods are released for shipment from the seaport of first arrival; and (3) distribute such information on a real-time basis to any Federal, State, or local government agency with a regulatory or law-enforcement interest in the goods.

(Sec. 14) Amends Federal shipping law to reauthorize specified tonnage duties.