"Leary" saw active combat duty during the war in the Vietnam War. The standard rotation for destroyers was a few months combat tour of duty at sea, usually around five months. At the conclusion of her tour of duty, the destroyer would return to port for maintenance, usually her home port. While in port the crew would receive leave and go ashore. When maintenance was complete, the crew would return from leave and the ship would spend a period of time undergoing tests or exercises near port. When exercises were finished, the ship would receive their orders and then return to sea for a new tour of duty. This was "Leary"s routine for her entire operational life.