United States Navy Armed Guard

United States Navy Armed Guard units were established during World War II in an attempt to provide defensive firepower to merchant ships in convoy or merchant ships traveling alone. This was done because of the constant danger from enemy submarines, surface raiders, fighter aircraft and bombers, and because of the shortage of Allied escort vessels necessary to provide the merchant vessels with adequate protection.

The United States Navy Armed Guard (USNAG) were U.S. Navy gun crews consisting of Gunner's Mates, Coxswains and Boatswains, Radiomen, Signalmen, an occasional Pharmacist's Mate, and toward the end of the war a few radarmen serving at sea on merchant ships.

Armed Guard crews served on Allied merchant marine ships in every theatre of the war. Typically the crew was led by a single commissioned officer, but earlier in the war chiefs and even petty officers had command.

The assignment as an Armed Guardsman was often dreaded because of the constant danger. Merchant ships were slow and unwieldy despite being priority targets for enemy submarines and planes. Furthermore, merchant ships were among the slowest to receive updated equipment. Early on in the war some ships only had a few machine guns installed, so the crew painted telephone poles to replicate the barrels of larger guns. The most common armament to be installed on merchant ships during the war were the MK II 20mm machine gun and the 3"/50, 4"/50, and 5"/38 deck guns.

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