The two leading contenders for the presidential nominations agree that the U.S. merchant marine needs to be strengthened, but they differ somewhat on the specifics of their maritime programs.

Vice President George Bush and Massachusetts Gov. Michael Dukakis also agree on the need to revitalize U.S. commercial shipyards, which have no commercial construction contracts. Their statements do not give details on exactly how that revitalization should occur. (Excerpts from their statements appear on Page 10A.)Both candidates responded to Journal of Commerce inquiries on their maritime policy. Responses from other candidates were not available.

Mr. Bush, the likely Republican nominee, focused primarily on the shipyard situation and the need to continue the Reagan administration's naval shipbuilding program in his statement.

We must make our merchant fleet stronger, he asserted.

He pointed to recent congressional action addressing the area of unfair maritime trade practices and the possibility of a domestic ship construction program as positive steps that will help in the stengthening process. A spokesman for Mr. Bush indicated the candidate might support bipartisan efforts on both those fronts.

I believe strongly that we must maintain this focus and positive leadership from the administration which is answered by responsible and effective congressional legislation, the vice president said in his statement.

A domestic shipbuilding program was one of the recommendations of the

Commission on Merchant Marine and Defense. The commission, created by Congress and appointed by the president, also recommended formulation of a national maritime policy and revision of the maritime subsidy system.

While both candidates touched on some items in the commission's January recommendations, neither specifically addressed the commission's work.

Gov. Dukakis, the front-runner for the Democratic nomination, addressed a wider range of maritime issues in his statement. He said he is disturbed by the massive decline of both the merchant marine and domestic shipbuilding capability.

We need our basic industries; industries such as steel and energy and shipbuilding and the merchant marine. And there is no reason why industries that have been depressed in recent years cannot turn around and come back strong, he said.

The governor said the next president should shift defense spending priorities in order to place greater emphasis on our conventional military capabilities, including U.S. ability to provide airlift and sealift in time of war.

The president should work with the industry and the government to increase the merchant marine's ability to contribute to sealift needs, he said.

Mr. Dukakis declared he will work with Congress to develop a national maritime policy aimed at reviving the morale and stimulating the resurgence of our merchant marine.

The governor pledged to enforce fully and fairly existing cargo preference laws that reserve a portion of government and military cargoes to U.S.-flag carriers.

Mr. Bush's statement was silent on that point, although the administration has espoused a similar view on cargo preference.

The vice president vowed to continue the administration's commitment to the strongest resurgence of sea power in the nation's history.

Mr. Bush commended the maritime industry for improvements in productivity and said this has created a good public perception where previously cynicism prevailed concerning over-pricing, delays and rumors of corruption.

The time is right for the maritime industry and the government to build upon these positive developments in shipping and the public perception that they have engendered to cooperatively work toward a strengthened merchant marine fleet, he concluded.

Gov. Dukakis said attention also should be directed to international worker rights, which he called a contributing factor to the decline of the merchant marine: American workers cannot be expected - and should not be asked - to compete with workers who are denied their basic rights.