The German U-Boat Type XXI, which was developed during the later stage of WWII, was a significant milestone in vessel-building history. This diesel powered U-Boat adapted a streamlined layout, which not only allowed it to travel undersea faster but also made it difficult to be detected by enemy sonar. Moreover, its onboard food refrigerating device also enables its crew to carry out long-term underwater missions.
Unlike its predecessors that had to rise up to sea level for torpedo launching, the Type XXI, equipped with hydraulic torpedo tubes, was able to launch and reload torpedoes 120 meters under sea level, making it the first submarine capable of underwater combat.
Although appeared too late to turn the tide of war, a total of 118 Type XXI U-Boats were produced from spring 1944 till the end of the war, posing a serious threat to Allied escort fleets in the Atlantic. Nevertheless, its advanced design had also become a paragon for many modern submarine designs.
Note: This is a detailed plastic model designed for display - to convert to use in Cruel Seas will take a modicum of skill