To reduce the Harbor Maintenance Tax, amend its applicability and enhance its enforcement.

Amends the Internal Revenue Code to reduce the harbor maintenance tax.

Prohibits such tax from being imposed more than once per cargo movement under the same bill of lading, regardless of how many times a cargo is loaded or unloaded under the same bill of lading.

Authorizes the expenditure of funds in the Harbor Maintenance Trust Fund for the payment of administrative expenses incurred by the Department of the Army and the Department of Commerce in administering such tax. Authorizes appropriations to the Department of the Treasury from such collected tax for enforcement activities to ensure that the tax is collected in all instances in which it is due.