170915-N-SH284-077 KEYPORT, Wash. (Sept. 15, 2017) Retired Capt. Don Walsh speaks about his time as the pilot of the Bathyscaphe Trieste, one of only two manned submarines ever to explore the deepest part of the ocean, the Challenger Deep in the Marianas Trench, during the Bathyscaphe Trieste Alumni Association bi-annual reunion at the Naval Undersea Museum-Keyport. Trieste II, the first deep submergence vehicle built by the U.S. Navy, following its acquisition of the original Trieste bathyscaphe, is permanently on display outside of the museum. (U.S. Navy photo by Mass Communication Specialist 2nd Class Vaughan Dill/Released)