[4] The beginnings of the company date to 1927 when Roberto Galeazzi patented a hydrostatic pressure-resistant submarine hull.

The patent was then approved by the Regia Marina which led to Galeazzi designing hulls for the Calvi-class submarines in the 1930s.

In 1932, Galeazzi's company also produced the butoscopic turret designed and used by Alberto Gianni in the salvage of SS Egypt.

[5] Also in the 1940s, the Galeazzi company provided diving equipment for the Italian Navy special forces.

The two companies then succeeded in the first operational saturation diving with the Capshell system at Porto Santo Stefano in the same year.

[3] Since then, Drass has built vessels for both the Italian military and the export market,[9] with the company's DG class of midget submarines presented at the Euronaval 2016 exhibition in Paris.