Coast Guard Reserve Port Security Unit 301 boarding team members clear a room during Boarding Team Member training on Coast Guard Base Cape Cod, Massachusetts, Wednesday, March 29, 2017. Using blue guns, members of PSU 301 go through a ship-in-a-box which simulates the inside of large ships such as a cargo vessel. (U.S. Coast Guard photo by Petty Officer 3rd Class Nicole J. Groll)