In this photo, a Conductivity-Temperature-Depth array rests on the deck of the American Diver while the ship transits to meet the Pisces, a NOAA fisheries survey vessel that is using a CTD to conduct sub-surface oil surveillance near Grand Isle, Sept. 14, 2010. Various sub-surface oil assessment techniques are being used off the coast of Louisiana in an effort to track, monitor, and measure oil remnants from the spill. U.S. Coast Guard photo by Petty Officer 2nd Class Etta Smith.