US National Archives Photo # 80-G-252172
This report presents Southsea Sub-Aqua Club’s 2022 investigation into two World War II wrecks long believed to be the US Landing Ship Tanks (LSTs) 496 and 523, lost during Operation NEPTUNE – the naval phase of the D-Day landings. Drawing on diver surveys, photogrammetry, multibeam sonar and historical research, the project set out to document the wrecks, preserve their stories, and honour the crews who served during the Normandy campaign. The team worked under licence from the French cultural authorities (DRASSM), combining archaeological techniques with detailed archive study to better understand these vessels’ final moments.
The findings challenge decades of accepted identification. The site traditionally marked as LST-523 displays extensive, intact structural features, vehicle cargo and bow-door damage consistent with an LST, but the team’s analysis indicates this wreck is in fact USS LST-496, lost on 11 June 1944. Conversely, the site believed to be LST-496 contains only a small debris field and two vehicle-sized engines, strongly suggesting it is not an LST at all, but instead likely a Landing Craft Mechanised (LCM) or unrelated WWII debris. This report sets out the survey evidence, historical context, and final conclusions, contributing to the ongoing effort to accurately document and protect the maritime heritage of the Normandy landings.