Galatin was born in New York City, on September 24, 1910, son of Ignatius Peter and Mary Elizabeth (Binder) Galantin.

In June 1940 he reported as executive officer and navigator of USS S-24 (SS-129), which was transferred to the British early in the World War II period by lend-lease agreement.

Thereafter, in June 1943 he joined USS Sculpin (SS-191) as Prospective Commanding Officer and participated in one war patrol in the Pacific area.

From August 1943 until December 1944 he was in command of USS Halibut (SS-232), which was awarded the Navy Unit Commendation for her tenth war patrol.

He took part in the Battle of Leyte Gulf as Commanding Officer of Halibut, and sank a large Japanese warship off Cape Engamo, P.I.

During the period June to November 1945, he served as operations and gunnery officer on the Staff of Commander Submarine Task Group, Saipan.

Upon his return to the United States in November 1945, he was ordered to the Staff of Commander Submarines, Atlantic Fleet, and served as personnel officer until July 1947.