sentences:  Confirmed by the Senate on December 16, 2015, Tidd received his fourth star and succeeded John F. Kelly as commander of United States Southern Command on January 14, 2016.Tidd holds the title of "Old salt", which means he received his qualification for Surface Warfare before any other active-duty navy officer.Upon the May 30, 2018, retirement of his United States Naval Academy classmate, Admiral Harry B. Harris Jr., Tidd also gained the honorific of "Old Goat" – the longest-serving Naval Academy graduate on active duty.