Sea Hunter Trials Sea Hunter, a new class of unmanned ocean-going vessel gets underway on the Williamette River, Portland, Ore., April 7, 2017, following a christening ceremony attended by Deputy Defense Secretary Bob Work. The vessel is part the of the Defense Advanced Research Projects Agency‘s Anti-Submarine Warfare Continuous Trail Unmanned Vessel program. Navy photo by John F. Williams SHARE: Download: Full Size (1.11 MB) Credit: John F. Williams VIRIN: 160407-N-PO203-598A.JPG Photo Gallery