Esper on the Boise Defense Secretary Dr. Mark T. Esper boards the USS Boise nuclear-powered fast attack submarine with Cmdr. Kris Lancaster, Norfolk, Va., Sept. 25, 2019. SHARE IMAGE: Download Image: Full Size (0.71 MB) Tags: Navy, Defense Secretary, Esper Photo By: Lisa Ferdinando, DOD VIRIN: 190925-D-BN624-0325.JPG Photo Gallery