Germany devastated Allied ships in the Atlantic, thanks to the new wolf pack tactic in 1940.

The Nazi campaign to send U-boats across the Atlantic to the U.S. at the beginning of Operation Drumbeat.

U.S. submarine skippers change the course of the WWII after entering the war and taking the fight to Japanese warships.

A 3-day clash between Nazi U-boats and Allied ships in March of 1943 marks a major turning point in World War II.

In June of 1944, American skipper Sam Dealey leads a rescue mission in Borneo.

Submarine skipper Dick O'Kane and the USS Tang sink Japanese ships through 1944, until their reign is threatened.