United States Merchant Marine

The United States Merchant Marine refers collectively to U.S.-flagged commercial vessels, both privately and federally owned, and the civilian mariners who crew them. Both the civilian mariners and the merchant vessels are managed by a combination of the government and private sectors, and engage in commerce or transportation of goods and services in and out of the navigable waters of the United States.

The Merchant Marine primarily transports domestic and international cargo and passengers during peacetime, and operates and maintains deep-sea merchant ships, tugboats, towboats, ferries, dredges, excursion vessels, charter boats and other waterborne craft on the oceans, the Great Lakes, rivers, canals, harbors, and other waterways. In times of war, the Merchant Marine can be an auxiliary to the United States Navy, and can be called upon to deliver personnel and materiel for the military.

In the 19th and 20th centuries, laws fundamentally changed American merchant shipping. These laws put an end to common practices such as flogging and shanghaiing, and increased shipboard safety and living standards. The United States Merchant Marine is also governed by more than 25, as of February 2017, international conventions to promote safety and prevent pollution.

In 2022, the United States merchant fleet had 178 privately owned, oceangoing, self-propelled vessels of 1,000 gross register tons and above. Nearly 800 American-owned ships are flagged in other nations.

The federal government maintains fleets of merchant ships managed by the United States Maritime Administration. In 2014, they employed approximately 6.5% of all American water transportation workers. Merchant Marine officers may also be commissioned as military officers by the Department of Defense. This is commonly achieved by commissioning unlimited tonnage Merchant Marine officers as Strategic Sealift Officers in the United States Navy Reserve.