Deutsche Schiff- und Maschinenbau Aktiengesellschaft (abbreviated Deschimag) was a cooperation of eight German shipyards in the period 1926 to 1945.

While the largest shipbuilding companies in Germany as Blohm & Voss and Bremer Vulkan AG because of their own strong market position at that time were not interested in this cooperation, eight other large German shipyards merged.

At least only AG Weser and Seebeckwerft survived this process of concentration and reduction of shipbuilding capacities.

In 1941 Krupp, then the most important German engineering and armaments conglomerate, acquired a majority shareholding in both shipyards.

Due to mismanagement and unsatisfactory and too late responses to market demands AG Weser was declared bankrupt in 1983 and operations were shut down while Seebeck shipyard became part of the Bremer Vulkan Verbund AG.