Born in Valmeyer, Illinois, in 1930, Trost entered the U.S. Naval Academy in 1949. He was commissioned an ensign in 1953, graduating first in his class. He reported to the destroyer USS Robert A. Owens (DDE-827) and in 1954 was detached to attend the Submarine School, New London, Connecticut. In 1955 he reported to the diesel submarine USS Sirago (SS-485), where he qualified as a submariner in 1956. In 1957 he attended the Advanced Nuclear Power course at the Submarine Base, New London, Connecticut, followed by training at the Naval Nuclear Power Training Unit, Idaho Falls, Idaho. In 1957 Trost reported to the nuclear-powered attack submarine USS Swordfish (SSN-579) and in 1959 qualified to command submarines. He studied German at the Army Language School, Monterey, California, in 1960 and then reported to the University of Freiburg, Federal Republic of Germany, serving until 1962, when he reported as executive officer of the nuclear-powered attack submarine USS Scorpion (SSN-589). In 1963 Trost attended the Polaris command course at the Fleet Anti-Air Warfare Training Center, Dan Neck, Virginia. He then reported as executive officer of the Blue crew of the nuclear-powered ballistic missile submarine USS Von Steuben (SSBN-632). In 1965 he reported as military assistant to the Deputy Secretary of Defense, Washington, D.C. In 1968 Trost assumed command of the Blue crew of the nuclear-powered ballistic missile submarine USS Sam Rayburn (SSBN-635). In 1969 he was assigned as Assistant Chief of Staff for Personnel and Administration on the staff of Commander Submarine Force, U.S. Atlantic Fleet. He reported in 1970 as executive assistant and naval aide to the Under Secretary of the Navy, and later Secretary of the Navy, John W. Warner. In 1973, his selection to flag rank was approved by the President. Trost assumed command of Submarine Flotilla One (later renamed Submarine Group Five) in San Diego, California, with additional duties as Commander Submarine Force Pacific Representative, West Coast. Trost reported to the Bureau of Naval Personnel as the Assistant Chief for Officer Development and Distribution In 1974, and in 1976 was assigned to the Office of the Chief of Naval Operations as Director, Systems Analysis Division, OP-96. In 1978, he was promoted to vice admiral and reported as Deputy Commander in Chief, U.S. Pacific Fleet, Pearl Harbor, Hawaii. In 1980, Admiral Trost assumed command of the U.S. Seventh Fleet and served in that position until 1981. For his service he was awarded the Government of Japan’s Order of the Rising Sun (Second Class) and the Republic of Korea’s Order of National Merit. His next assignment was as Director, Navy Program Planning, OP-090, on the staff of the Chief of Naval Operations. In 1985 he was promoted to the rank of four-star admiral and became Commander in Chief U.S. Atlantic Fleet and Deputy Commander in Chief U.S. Atlantic Command. Admiral Trost served as Chief of Naval Operations from 1986 to 1990.