Sunken Civil War gunboat mapped by sonar

New Scientist : On the 150th anniversary of the sinking of the USS Hatteras during the Civil War, the National Oceanic and Atmospheric Administration has completed a three-dimensional sonar map of its rusting remains. The Hatteras was an iron-hulled paddle-wheel steamship that was sunk on 11 January 1863 in the Gulf of Mexico by the Confederate CSS Alabama. Resting some 17 m underwater about 30 km off the coast of Galveston, Texas, the Hatteras was found largely intact by a local underwater photographer, Jesse Cancelmo, who reported that sand and sediment that had once buried the wreck had shifted due to recent storms. The Hatteras has protected status as a war grave because two crew members went down with the ship. Thanks to the 3D sonar, researchers and the public can now “virtually swim through the wreck’s exposed remains and even look below the surface at structure buried in loose silt,” said James Delgado of NOAA.