National Geographic - WW2: Hell under the Sea - Series 3 (2020)

Hell Under the Sea is heading to new heights in Season 3 when series takes a deep dive into the undersea battles that changed the course of World War II.
Submarines demand a special breed of warrior–volunteers and never conscripts, self-sufficient enough to operate far forward of logistical support and any chance of rescue. Tenacious and aggressive, submariners often fight alone. Expert analysis and stock footage are woven with narrative driven re-enactments placing the characters at the heart of the action.
"Hell Under the Sea" traces the course of submarine warfare in World War II and leads to important battle locations in the Atlantic and Pacific.

Part 1: Killer Strike
September 1939. After being credited with the first official U-Boat kill of the Second World War when he sinks the SS Bosnia, German U-Boat commander Gunther Prien is abruptly recalled from patrol early and offered a secret mission to strike the Royal Navy at its home port of Scapa Flow. Fighting heavy currents and dodging blockships, Prien breaks into the anchorage, but there is not guarantee he will make it out again.

Part 2: Enigma Capture
May 1941. The life of German U-Boat commander Fritz Julius Lemp takes a series of dramatic turns as he risks the wrath of Adolph Hitler with a torpedo salvo that sinks the passenger liner SS Athenia in error, and then tangles with the ships and aircraft of British carrier group, as Germany tries to prevent the United States from joining the war on the side of Britain.

Part 3: The Longest Journey
December 1944. A German U-Boat Commander makes an unprecedented voyage to attack Allied shipping off the coast of Australia. On Christmas morning, the gun crew of a merchant ship fights back and destroys a torpedo destined for their ship, but with the U-Boat circling for another shot, can they hold out until help arrives?

Part 4: Torpedo Rampage
July 1944. After a lackluster wolfpack operation, an American submarine commander penetrates the defenses of a Japanese convoy in the Luzon Strait. Under constant threat from the convoy's escorts, the submarine dodges enemy fire and launches a series of attacks. But when their torpedo tubes are empty, the defenseless crew risks everything to stay in the fight.

Part 5: Commander Down
February 1943. After facing down three destroyers in the Japanese occupied harbor of Kiska, Alaska, an American submarine takes the fight to the south Pacific. On a stormy night, they locate a Japanese ship and circle for an attack. Rain and darkness obscure their target-and the Commander realizes too late, how close the enemy is.

Part 6: Iwo Jima Pilot Rescue
When the Allies use carrier groups to deliver destruction to the strongholds of the Imperial Japanese Empire, aircraft and airmen prove vulnerable. Only one kind of vessel has a chance to sneak in, surface and perform rescues in enemy waters. As the Submarine Lifeguard League mobilizes, American subs risk everything to rescue downed aviators.