USS Mero (SS-378), a Balao-class submarine, was a ship of the United States Navy named for the mero, any of several large groupers found in warm ocean waters.

Mero got underway for shakedown in Lake Michigan 25 August; thence, between 6 September and 17 November she cruised the Great Lakes and visited several ports including Detroit, Cleveland, and Chicago.

The Mero tied up at The Michigan Avenue bridge in Chicago and was open to visitors who were allowed aboard for a tour of the boat.

On 20 April 1960, Mero was transferred on loan to Turkey under the Military Assistance Program.

After her voyage from San Francisco, Hızırreis was commissioned into Turkish Navy service on 23 August 1960.