GROTON, Conn. (Mar. 15, 2018) Sailors assigned to Pre-Commissioning Unit Colorado (SSN 788) salute the national ensign during their commissioning ceremony practice. Colorado is the the U.S. Navy's 15th Virginia-class attack submarine and the second ship named for the State of Colorado. (U.S. Navy photo by Mass Communication Specialist 1st Class Jeffrey M. Richardson/Released)