To amend the Internal Revenue Code of 1986 to provide that the harbor maintenance tax shall not apply to the movement of certain cargo within contiguous United States and foreign ports, and for other purposes.

Amends the Internal Revenue Code to extend the exemption from the harbor maintenance tax for intraport movements to cargo movement between a U.S. port and a port located in a foreign country which is within five miles of such U.S. port (a unified port). Declares that such exemption does not apply to: (1) cargo landed in such foreign country before landing in the unified port; or (2) cargo destined for use outside the United States and outside such foreign country.

Increases the rate of the harbor maintenance tax.