Under federal law the Department of Homeland Security has general superintendence over the merchant marine, the industry and its seafarers.
Seafarers already have been burdened with extra security duties aboard ship under the Code of Federal Regulations.
There are 95,000 miles of coastal shorelines for the U.S. that the Coast Guard cannot fully patrol.
The U.S. Merchant Marine Auxiliary would augment coastal patrols in addition to serving as a resource for privateers under Letters of Marque and Reprisals.
This is a constitutional approach for the "Common Defence."