The heavy cruiser remained at Norfolk into the New Year, 1940, and departed her home port on 11 January bound for the West Indies. On the voyage to the Caribbean, she was accompanied by her sister ship "San Francisco"; Battleship Division 5—less and , the prototype high-speed transport. "Tuscaloosa" and her consorts arrived at Culebra on the 16th, and two days later shifted to Guantánamo Bay. There, she participated in fleet exercises from the 18th to the 27th. Departing Guantánamo on the latter day, the "Tuscaloosa" returned to Norfolk on 29 January and entered the navy yard there for special alterations to fit her out for service as presidential flagship.