The U class paired compact displacement with weapons and endurance suited to close Mediterranean operations. Wartime batches dropped the two external, non-reloadable torpedo tubes and improved surfaced endurance. HMS Upright attacked Italian shipping and a floating dock, while Polish-crewed ORP Dzik damaged or destroyed roughly 18 ships totaling 45,080 tons. A fully submerged U-class boat displaced about 730 tons, so Dzik's record conveys the effect a small submarine could have when operating from nearby bases in a target-rich and heavily defended sea.
Notable Point · 43:35-49:05
U-class boats and aggressive Mediterranean patrols
Small U-class submarines achieved substantial results in the Mediterranean, including boats operated by Polish crews.