Survey shows striking legacy of Operation Dynamo on the seabed off Dunkirk

Between 25 September and 8 October, the French marine heritage agency, Drassm – in partnership with Historic England – surveyed 30 wrecks sunk during Operation Dynamo. The survey shows the position, characteristics and condition of each wreck in remarkable detail. Seeing these wrecks in such detail for the first time is a powerful reminder of the scale and human cost of the evacuation.

The operation was led by Drassm archaeologists Cécile Sauvage and Claire Destanque aboard a Drassm research vessel – the André Malraux – captained by Fabien Géreux from Bourbon Offshore Surf. Drassm geophysicist Alexis Rochat was joined by a UK geophysicist, Mark James of MSDS Marine, commissioned by Historic England for this role. The survey is the first collaboration between Drassm and Historic England and provides essential information for researching and managing these wrecks in future.

Research Vessel André Malraux off Dunkirk. © CUD/Ville de Dunkerque.

Duncan Wilson, Chief Executive of Historic England, said: “It is very moving to see new details emerge from 30 shipwrecks linked to Operation Dynamo for the first time since the events at Dunkirk during the Second World War. We are pleased that a geophysicist from the UK, commissioned by Historic England, has been integral to the survey that has successfully captured these details alongside Drassm’s incredible team of scientists. The results give us a striking insight into our shared heritage that still lies beneath the waters off Dunkirk.”

The principal instrument used for the survey is a multibeam echosounder mounted beneath the hull of the André Malraux. The instrument emits a fan of sound that is recorded as it bounces off the seabed. The data is used by geophysicists to create a highly detailed three-dimensional image of seabed features such as shipwrecks. 27 wrecks from Operation Dynamo were located and studied during the survey. The position of 12 of these wrecks was not known precisely before the survey. Four wrecks, either destroyed or covered by sand, could not be found.

A further 19 features have been studied, three of which appear to correspond to the location and characteristics of vessels lost during Operation Dynamo that were previously undiscovered.

Archive photograph of the trawler Denis Papin
Multibeam survey of the wreck of the Denis Papin. © Drassm, multibeam processed by A. Rochat (Drassm) and M. James (MSDS Marine/Historic England).

The identities of two wrecks – the French auxiliary minesweepers Denis Papin and Moussaillon sunk by air attacks on 1 June 1940 – have been corrected. The new data demonstrates that previous identifications had confused the two wrecks.

The survey data was detailed enough to confirm the identification of 19 wrecks: dimensions and distinguishing features from the survey corresponded to documented dimensions of the vessels and to features on historic photographs. On one wreck, the davits from which lifeboats once hung can be seen in the survey data: their precise form – together with other details and dimensions – confirm that it is the Normannia, requisitioned as a troop carrier and sunk by an air attack on 30 May.

New multibeam survey of the wreck of the destroyer HMS Keith, showing the displaced hull section. © Drassm, multibeam processed by A. Rochat (Drassm) and M. James (MSDS Marine/Historic England).

The survey has confirmed that many of the Dynamo wrecks are in relatively good condition. However, the new data also shows recent changes. The destroyer HMS Keith was surveyed in 2016 and 2019 by the Port of Dunkirk (Grand Port Maritime de Dunkerque – GPMD): the 2023 survey shows that part of the destroyer’s hull has degraded in just a few years, collapsing away from its former position.

This is the first stage of a multi-year project. The 2023 survey will provide baseline information for diving investigations starting in partnership with local divers in 2024. All this information, enhanced by further research, will be made available to the public through museums and online as the investigations progress.

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