James T. Kirk had his first deep-space assignment under Garrovick, who was one of the finest men Kirk had ever known. During a mission to Tycho IV in 2257, Garrovick and two hundred of his crew were killed by a dikironium cloud creature.
Kirk felt terrible guilt over his captain's death; it was not until many years later that Kirk learned that there was very little he could have done to prevent the disaster, as phaser fire had no effect upon the creature. (TOS: "Obsession")
DC Comics Who's Who in Star Trek mentions Captain Garrovick's first name as "Stephen" in the profile entry for his son, John Garrovick. His personality was described as "stern but likeable".