USS Gem of the Sea (1861) was a bark acquired by the Union Navy during the American Civil War. She was used by the Navy to patrol navigable waterways of the Confederacy to prevent the South from trading with other countries. Gem of the Sea was purchased at New York City from Galway & Teller 3 August 1861; and commissioned 15 October, Acting Volunteer Lt. Irvin B. Baxter in command.