On the Water

Merchant Seamen

The seamen of the Merchant Marine kept open a lifeline of supplies to fighting forces overseas.

During World War II, U.S. shipyards turned out cargo vessels faster than the ships could be supplied with crews. Recruiters urged men to join the Merchant Marine, and volunteers came from across the country. Some had never seen the ocean and others came out of retirement. Merchant seamen ran the ships that carried supplies and men through dangerous waters in the North Atlantic and the Pacific. Thousands paid with their lives. By war’s end, some 290,000 men had served in the Merchant Marine.

But for the lives that were lost on these ships...we wouldn’t have our freedom today.
—Capt. Frank Medeiros, USMS (Ret.)
  • Teamwork Wins: You Build ’Em, We’ll Sail ’Em, 1943

    People and ships to win the war was the theme of posters produced by the United States Maritime Commission, the government agency responsible for the nonmilitary maritime war effort.

    Courtesy of the National Archives and Records Administration

  • Poster, You Bet I'm Going Back to Sea [1942]
    Poster, You Bet I'm Going Back to Sea

    You bet I’m going back to sea, 1942

    View Object Record

    U.S. Merchant Marine War Shipping Administration

Merchant Mariners

Educational Resources

Listen to the stories of Merchant Mariners and shipyard workers and work with primary sources to uncover the answers to historical questions about World War II.

Seamen in the Merchant Marine came from all corners of American society. Recruiting standards differed from those of the armed forces, so thousands of men excluded by the military served their country aboard merchant ships. They ranged in age from 16 to 78. Some men had weak hearts, poor vision, or other disabilities, but their service was essential to the war effort. The Merchant Marine was more racially integrated than any of the branches of the service.

Young men trained as ships’ officers at the U.S. Merchant Marine Cadet Corps, established in 1938 at the Merchant Marine Academy in King’s Point, New York. By the end of the war, 6,000 new officers had been trained.

  • Loading a Liberty

    Merchant mariners load war vehicles into the hold of a cargo ship in New York Harbor, September 1944.

    Courtesy of the National Archives and Records Administration

  • Free Time on a Liberty

    Like other sailors in downtime at sea, Liberty ship crews played cards, read, and tried to distract themselves from the intensity of wartime service. The crews included members of the Armed Guard of the U.S. Navy, shown here in navy uniforms, who manned the guns aboard ship.

    Courtesy of the U.S. Maritime Commission

All we cared is that you did your work.
—Bill Bailey, Engine Department, USMS
It’s the old timers who made seamen out of them.
—Pete Goodman, Engine Department, USMS
Model, Liberty Ship [early 1940s]
Model, Liberty Ship

Liberty cargo vessel (type EC2-S-C1)

Gift of the U.S. Maritime Commission

Liberty Ship

View Object Record

Liberty ships were as crucial to the Allied war effort during World War II as any tank or fighter plane. Nearly everything the Allies needed to fight in Europe and the Pacific arrived in ships—tanks, locomotives, tractors, tires, ball bearings, ammunition, fuel, food, and cigarettes, to name only a few. Naval vessels were first in line for new steam turbine engines, so Liberty ships were built with tried-and-true reciprocating steam engines—reliable but slow.

By the end of the war, 2,600 Liberty ships had entered service.

Ship Model, Victory Ship Type VC2-S-AP [early 1940s]
Ship Model, Victory Ship Type VC2-S-AP

Victory cargo vessel (type VC2-S-AP)

Gift of the U.S. Maritime Commission

Victory Ship

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Faster freighters had a better chance of surviving a transoceanic crossing in hostile waters. As steam turbine engines became available later in the war, a few shipyards began building more powerful cargo vessels—called Victory ships. American shipyards built about 550 by the end of 1945. After the war, their greater speed made them more valuable as commercial freighters.

Perils of War

During World War II, the seamen of the U.S. Merchant Marine suffered a higher casualty rate than any service branch. As many as 9,500 perished at sea, from their wounds, or in prisoner of war camps.

At the end of the war, they received no government pensions or benefits and could not take advantage of the GI Bill. Celebrations for returning heroes usually overlooked them. Only in 1988 were seamen of the Merchant Marine granted the same benefits as other veterans. By then, fewer than half the men who had served on Liberty ships were still alive.

There weren’t any parades for the United States Merchant Marine.
—Rear Admiral Thomas Patterson, United States Merchant Service (Ret.)

Waldemar Semenov and the SS Alcoa Guide

On April 16, 1942, a German submarine surfaced near the SS Alcoa Guide off the coast of Cape Hatteras, North Carolina, and opened fire with its deck gun. Unarmed and without an escort, the ship sank in two hours. But Junior Engineer Waldemar Semenov and 26 of his shipmates survived. In two lifeboats, the men drifted for three days until they were spotted by a search plane. The next day, the USS Broome, a Navy destroyer, picked them up. Semenov’s ordeal didn’t drive him from the sea. He continued to work as a merchant seaman until his retirement in 1987.

  • In the Lifeboat

    Twenty-eight-year-old Semenov did not panic as his ship came under fire. Before climbing into a lifeboat, he went below, grabbed his camera, and changed into a suit he had recently bought in New York. One of his shipmates took this photograph of Semenov in his suit.

  • Awaiting Rescue

    While passing the time at sea, Semenov took pictures of the survivors in his lifeboat.

  • Signaling Mirror [1955-56]
    Signaling Mirror

    Signal Mirror

    View Object Record

    Signal mirrors were standard equipment for seamen on Liberty ships in case they were stranded at sea. Part of the instructions read: “Even though no aircraft or ships are in sight, continue sweeping the horizon. Mirror flashes may be seen for many miles, even in hazy weather.”

    Gift of Waldemar Semenov

  • Boat Compass [late 1930s]
    Boat Compass


    View Object Record

    Junior engineer Waldemar Semenov and his shipmates used this compass to guide their lifeboat toward Florida after a German submarine sank their ship in the Atlantic, April 1942.

    Gift of Waldemar Semenov

In their own words

Meet several merchant mariners who sailed on cargo vessels, including Liberty ships, during World War II. Each survived the perils of wartime service. Hear their stories, in their own words.

  • Allied tanker sinking in the Atlantic Ocean after being torpedoed by a German submarine, 1942

    Courtesy of the National Archives and Records Administration

  • American cargo ship exploding after being hit by German aircraft in the invasion of Sicily, 1943

    Courtesy of the Library of Congress