A U-boat coming to the surface after being damaged.
U-boat, German abbreviation for Unterseeboot, is the German collective name for any submarine as the name U-boat stands for undersea boat. However, U-boat is also the name commonly given by the Allies to any German war-submarine that has the purpose of sinking ships, doing cargo runs, or going on patrol. U-boats were the main force deployed by the Kriegsmarine during the Battle of the Atlantic and were highly effective in the role that they were often assigned to which was to disrupt enemy shipping.