Investigating the Lost Sherman DD-Tanks of Omaha Beach

Seventy years ago today, on 6th June 1944, the largest seaborne invasion in history, code-named Operation Neptune better known as D-Day, began on the Normandy Beaches in Northern France. This began the invasion of German occupied Western Europe helping to secure the eventual Allied victory. But it also resulted in one of the largest losses of life during an assault, at Omaha Beach.

Sherman DD-Tank
Sherman DD-Tank from WWII with the canvas skirt lowered*

Despite poor weather conditions and due to the complexity of the planned invasion, which took into account phases of the moon, tides and time of day, the assault went ahead a day after the original planned date of 5th June. The less than ideal weather conditions proved insignificant at four of the five sections of the beach, but were disastrous for the US 741st Tank Battalion. 


The 741st Battalion was made up of specially modified Sherman tanks that were outfitted with a canvas skirt and duplex drive mechanism, converting them into amphibious vehicles that would be the first to approach the beach. The canvas skirts allowed the tanks to float low in the water making them appear as small boats from the shore. In the calmer waters of the surrounding sectors of Omaha the Sherman DD-Tanks generally worked well and provided much needed support to the infantry assault. However, having been launched an extra 1.5km further at sea than planned and with six foot swells – the canvas skirt having only been designed for one foot – just two of the first twenty nine tanks launched made it to shore.

Prior to 2000 no underwater archaeology, to document the remains of the assault, had ever been conducted until the Institute of Nautical Archaeology at Texas A&M University began researching the site. Using state of the art remote sensing, detection and imaging equipment the submerged collection of DD-Tanks was identified and became the focus of a BBC documentary, Journeys to the Bottom of the Sea – D-Day: The Untold Story, for which CSD provided full dive support, logistics and the underwater cameramen.


* Image Source –