Perhaps their most daring attack at the Japanese Empire came toward the end of the war when the crew of this submarine attacked a train in Karafuto Prefecture—what we now call the southern end of the Russian island of Sakhalin.
On July 23, 1945, the Barb approached the coast, sank a frigate, then surfaced about 950 yards offshore. 8 volunteers paddled ashore in rubber boats and walked 400 yards to a set of railroad tracks. They rigged explosives to the tracks, then returned to the Barb. As they paddled back, a 16-car military train passed by, activated the explosives, and blew up.
Here's a good short video on "Lucky Flucky and U.S.S. Barb"
It's such a good story.