180712-N-YG104-0080 SAN DIEGO (July 12, 2018) Fleet Master Chief Russell Smith observes Sailors conducting second phase for Basic Underwater Demolition/SEAL training while visiting Naval Base San Diego and surrounding units. Fleet Master Chief Smith is temporarily assuming the roles and responsibilities of the Master Chief Petty Officer of the Navy. (U.S. Navy photo by Mass Communication 2nd Class Sarah Villegas/Released)