The bottom of the Baltic Sea is home to large quantities of sunken munitions, a legacy of the Second World War—and often very close to shore. Should we simply leave them where they are and accept the risk of their slowly releasing toxic substances, or should we instead remove them, and run the risk of their falling apart—or even exploding? Administrators and politicians face these questions when, for example, there are plans for building a new wind park, or laying an underwater cable. In the course of the international project DAIMON, researchers prepared essential decision-making aids, which were recently presented at the Thünen Institute in Bremerhaven/Germany.