Satellite Detection and the Discovery of Bloody Marsh

Assessment and mitigation of potentially polluting wrecks in deeper water is a more challenging endeavor due to limitations of divers and operating pumping equipment at depth, but additionally because locating these wrecks is harder. While these wrecks in deep water are more out of sight and out of mind, even when leaking, than those near shore, they are safer from damage by dredges, trawls or other anthropogenic activities. The wreck of the tanker SS Bloody Marsh, reportedly sunk off South Carolina on July 2, 1943 in 560 m of water, was considered a lower risk in NOAA’s PPW study due to its location in deep water, which the NOAA Screening Level Risk Assessment Packages typically considered as less risk: ‘deepwater shipwrecks tend to settle upright on the bottom, and is supported by the conclusions made by the U.S. Coast Guard in 1967 that oil will likely escape from a wreck’s vents and piping long before its hull plates corrode’ (NOAA, 2013b: 6). This, however, is a conclusion that needs to be reconsidered. Bloody Marsh was carrying a cargo of 106,496 barrels of bunker C heavy fuel oil, which is one of the largest cargoes among the vessels on the PPW list. In reviewing the 87 wrecks on the list, we selected Bloody Marsh as a high priority because of its large cargo and the fact that it was struck with two torpedoes and reportedly broke in half while sinking. Only ships with intact hulls would settle upright on the seabed, and therefore presumed Bloody Marsh did not.