The Ohio-class ballistic missile submarine USS Pennsylvania transits the Hood Canal as the boat returns to its homeport at Naval Base Kitsap-Bangor, Wash., Dec. 27, 2017, following a routine strategic deterrent patrol. The Pennsylvania is one of eight ballistic missile submarines stationed at the base, providing the most survivable leg of the strategic deterrence triad for the United States. Navy photo by Petty Officer 1st Class Amanda R. Gray