S2E5: North Sea Showdown aka Sub vs. Sub

In the icy waters off of Norway in 1945, a U-boat embarks on a mission to bring top-secret German technology to Japan, unaware that a Royal Navy V-class submarine has just been ordered to patrol the area. Neither commander manning their vessel realizes that they are about to face-off in the world's first underwater submarine dogfight. Witness the historic battle between HMS Venturer and U-864.