During the difficult years of the occupation, the DEME founders continued their activities in Belgium through a series of small-scale but essential works, mainly along the Scheldt and the Rupel rivers. Operating under constrained conditions, operating with a severely limited fleet and restricted resources, the company remained active in support of local industry and infrastructure. The founders carried out a series of targeted assignments for the Boel shipyard in Temse between December 1941 and January 1943. Deploying the bucket dredger Rupel and the hopper dredger Élévateur II, the teams executed essential embankment works, built a new dike, deposited sand, and raised the local causeway by 3.5 meters. These technical tasks kept crucial maritime infrastructure functional during a period of severe economic restriction. One of the few vessels that remained operational on the Scheldt River during the war was SGD’s Yperlee. The crew of this vessel protected themselves against sea mines and bombardments by placing sandbags on the deck.

At the same time, and despite the challenges of the war, the group remained involved in major maritime infrastructure projects abroad through its international network. Dredging and rock excavation works were e.g. carried out for the Royal Navy in Gibraltar, alongside a major military contract in Cherbourg that was halted due to bombardment. Though often limited in scale domestically, and carried out under constant constraints, these technically demanding works ensured continuity of operations, preserved critical expertise, and allowed the company to remain active during one of the most challenging periods in its history. The continuation of these works during the war years demonstrates a defining characteristic that remains central to DEME today: the ability to deliver complex projects while under pressure and in uncertain environments. Because even in a period that was shaped by huge disruption and conflict, maritime engineering activities continued, and they supported essential infrastructure and helped lay the foundations for future development.