Merchant Marine Act Bulk Shipping Amendments of 1979

Merchant Marine Act Bulk Shipping Amendments of 1979 - Amends the Merchant Marine Act, 1936, to allow proposed ship purchasers or United States' shipyards to apply to the Secretary of Commerce for financial aid for the construction and operation of vessels to be used in essential bulk cargo carrying services.

Makes such vessels, once constructed pursuant to plans and specifications approved by the Secretary and once documented under the laws of the United States, eligible for per diem financial assistance payable for each day the vessel is operated in foreign trade. Stipulates that such vessels shall be entitled to engage in all domestic trades without restriction of any kind and shall be entitled to enter or leave domestic trade upon giving the required notice as set forth in this Act.

Stipulates that such assistance shall consist of a construction component and an operating component.

Establishes a method for computing such assistance.

Reduces the time period during which a vessel which has received a construction-differential subsidy must remain documented under the laws of the United States. Stipulates that if such a vessel has held such documentation for less than 25 years then the net proceeds of the sale of the vessel must be transferred to the seller's Capital Construction Fund if the vessel was transferred to another nationality. Requires that such construction funds be committed within a period of two years to the construction of a qualified replacement vessel.

Stipulates that capital construction funds may be used to build vessels to operate in the coastwise, intercoastal, or noncontiguous trade.

Makes it unlawful for any individual receiving an operating-differential subsidy or a charter of a vessel owned by the Department of Commerce to act as an agent for, or operate, any foreign-flag vessel which competes with, any American-flag service determined to be essential by the Secretary of Commerce.

Requires each Federal department or agency to develop an affirmative action plan to insure that at least 50 percent of the cargoes procured or furnished by the agency or department shall be carried on United States-flag vessels. Subjects such plans to the approval of the Secretary. Prohibits any deviation from such a plan without the Secretary's approval.