151001-N-ZZ999-305 PACIFIC OCEAN (March 1, 2016) The 1,000 horse power triple-expansion steam engine inside the hull of the wreck of the U.S. Navy tugboat USS Conestoga (AT 54) in the Farallones National Marine Sanctuary. This diagnostic artifact help date the shipwreck along with its coal fired twin Scotch boilers. (U.S. Navy photo courtesy of NOAA/Released)