USS Gem of the Sea was a bark acquired by the Union Navy during the American Civil War.

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.

British schooner George was taken in the Sanibal River 29 July; and sloop Richard fell into her hands in Peace Creek 31 August.

From 24 to 30 December 1863, she was part of an expedition up the Myakka River, transporting refugee rangers from Useppa Island to the mainland.

This article incorporates text from the public domain Dictionary of American Naval Fighting Ships.