Ships
- USS Lamson (DD-367) Captain, 1 April 1941 – 12 June 1942
- USS Pittsburgh (CA-72) Captain from 25 September 1951
Preston Vigginius Mercer was born on 4 November 1901. He graduated from the United States Naval Academy in 1924 and was promoted to lieutenant commander on 1 May 1939. On 30 June 1939 he took command of the flush-deck destroyer Rathburne (DD-113), a ship completed in the First World War, and he had her again after a brief interval in March and April 1940.
On 1 April 1941 Mercer relieved Perley Earl Pendleton as commanding officer of Lamson (DD-367). Lamson was a Mahan-class destroyer built at Bath Iron Works and commissioned on 21 October 1936. When he came aboard she was already working from Pearl Harbor, the fleet's advanced base in Hawaii. His rank was still lieutenant commander.
The command ran from the last months of peace into the first half of the Pacific war. On 7 December 1941 Lamson was at sea on patrol when carrier aircraft attacked Pearl Harbor. In January 1942 Mercer took her to the South Pacific, where escort and patrol duty filled the rest of his time in the ship. He left Lamson on 12 June 1942. Walter Terry Jenkins then held her as officer in charge until 23 June 1942, and Phillip Henry Fitzgerald assumed command that day.
Mercer was promoted to temporary commander on 17 July 1942 and to temporary captain on 1 June 1943. On 25 September 1951 he assumed command of the heavy cruiser Pittsburgh (CA-72). The Baltimore-class ship had served in the Pacific during the Second World War and had been out of commission since 1947. She returned to service on the day he took her, and he was her commanding officer from that recommissioning.
Mercer died in 1970. His commands reached from an aging destroyer at the end of the 1930s, through Lamson in the opening months of the Pacific war, to Pittsburgh in 1951.