171125-N-TW634-055 ATLANTIC OCEAN (Nov. 25, 2017) Sailors assigned to Unmanned Undersea Vehicle Squadron 1 (UUVRON 1), mobilized with Undersea Rescue Command (URC), perform maintenance on a Bluefin-12D, an unmanned underwater vehicle, on board the Norwegian construction support vessel Skandi Patagonia near URC's submarine rescue chamber. Undersea Rescue Command, the U.S. Navy's only submarine rescue unit, is mobilized to support the Argentine government's search and rescue efforts for the Argentine Navy diesel-electric submarine A.R.A San Juan (S 42). (U.S. Navy photo by Mass Communication Specialist 2nd Class Derek Harkins/Released)