1. Tow-yo

The research team searched for evidence of plumes around the Deepwater Horizon riser pipe using a technique called a “tow-yo,” which oceanographers had perfected to search for plumes from hydrothermal vents of the seafloor. To tow-yo, researchers dangle a package of sensors into the ocean from a cable connected to a ship. The ship tows the cable horizontally while a winch alternately hoists the package up and lowers it down again like a yo-yo—in an effort to land the package within a plume. The crew of the research vessel Endeavor circled in a 3.1-mile radius nearly completely around the broken well, skillfully tow-yo-ing instruments between 2,600 and 4,600 feet deep on a mile-long cable in the sea.