Testing Density of Ocean Floor Navy Petty Officer 1st Class David Miller, left, and Navy Seaman Lucas Jackson test the density of the ocean floor during exercise Valiant Shield 2016 in Kwajalein, Marshall Islands, Sept. 16, 2016. Miller is a steelworker and Jackson is a construction mechanic constructionman are assigned to Underwater Construction Team 2. Navy photo by Petty Officer 2nd Class Daniel Rolston SHARE: Download: Full Size (1.7 MB) Tags: Sailors, training, Navy Credit: Petty Officer 2nd Class Daniel Rolston VIRIN: 160916-N-CN059-0163A.JPG Photo Gallery