Hell Below

An attack forces an American submarine into a disastrous dive, and the crew struggles to regain control while battling a chemical fire that threatens their air supply.

The career of a young U-Boat officer begins with promise when he is awarded command of his own submarine, but clashes over Nazi ideology cause tension.

Documentary series exploring the use of submarines in the Second World War.

When Hitler sends U-Boats to protect his troops, a German sub rushes towards the fjords leading to Narvik - the scene of two major naval battles.

A new submarine commander must overcome dissent despite his unconventional choices. The crew works together to build trust as they travel dangerous Japanese home waters.

Documentary series exploring the use of submarines in the Second World War.

After being credited with the first official U-Boat kill of the Second World War, 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.

As carrier groups deliver destruction to Japanese strongholds, American subs risk everything to surface in enemy waters and rescue downed aviators. Submarines featured are the USS Skate and USS Finback. Also covered is the Finback's rescue of future U.S. President George H. W. Bush.

USS Silversides and its swashbuckling skipper, Creed Burlingame, saw their first action in the Pacific in May 1942. More than a dozen patrols later, the sub now rests in Muskegon, Michigan as a museum, an ongoing testament to its extraordinary history. Witness one of Silversides' most dramatic missions: aiding Marines in Guadalcanal by keeping Japanese reinforcements from reaching the island. It's an assignment fraught with depth charge attacks and aerial bombardments that nearly ended the mission and its crew. The sub experienced a jammed torpedo and an emergency appendectomy whilst intercepting Japanese ships deep in enemy waters. 

June 1945. With Japanese merchant shipping slowed to a trickle, US Medal of Honor Recipient, Commander Eugene Fluckey plots to destroy shore based targets along Japan's coast - a campaign that develops unprecedented tactics.

In January 1944, the U-515, commanded by Werner Henke, defies the odds and escapes both Allied depth charges and aircraft to sink ships and return to port despite severe damage. Ten weeks later, the German U-Boat is put to the ultimate test. In April 1944, U-515 heads to the African Gold Coast, where it is tested by one of the new Hunter Killer Groups led by Captain Daniel Gallery.

It's 1941, and German Gen. Erwin Rommel and his armies hope to take Egypt, gain control of the Suez Canal, and prevent Britain from receiving vital supplies from the colony of India and the Middle East. The Allies' last line of defense is a fleet of small, British Royal Navy U-class subs stationed on the tiny island of Malta. Despite unpredictable weather and a broken gyrocompass, HMS Upholder and its Lieutenant-Commander Malcolm Wanklyn hunt Italian supply ships to hold the line against the Axis powers and turn the tide of the North African Campaign.

February 1945. Below icy Norwegian waters HMS Venturer stalks German U-Boat 864 in a rare WWII submarine attack where both subs operate submerged.

When Soviet submarine, B-59, is discovered "practice depth charges" are dropped; nearly inciting a nuclear war.

The wolfpack tactic was made famous by Admiral Karl Donitz, Hitler's mastermind of submariners. His strategy: to send teams of U-boats to bear against the convoys of ships heading from Canada to Britain, cut maritime lifelines, and starve the enemy into defeat. Take a deep dive into the North Atlantic as we go above and below sea level to relive one of the first attacks of Donitz's lethal subs in 1940, headed by leader of the pack Commander Otto Kretschmer. Then follow Britain's war strategists as they race to combat this new deadly attack.

Just one month after the Japanese attack on Pearl Harbor, another enemy brought World War II to American shores, not through the air but beneath the sea. This is the story of Operation Drumbeat, German Admiral Karl Donitz's campaign to send U-boats to the doorstep of the U.S. and attack Allied merchant shipping from Newfoundland to North Carolina. Through archival war footage and military expert testimony, we reveal how the Nazis managed to hammer our coast again and again and why the U.S. Navy was unable to stop them.

It's January 1943 in the Pacific and American submarine skipper Dudley Morton is just 10 days into his first patrol aboard USS Wahoo. His mission: to sink Japanese ships and disrupt supply lines. This aggressive strategy is a radically new tactic for the U.S. Navy, and Morton is just the man to carry it out. See these water wars up close and witness Morton take on entire Japanese convoys above and below the Pacific in this thrilling exploration.

A Nazi U-boat heading back for repairs unintentionally cruises right into the middle of a large Allied convoy on March 16, 1943. It is a lucky accident that sets the stage for the largest convoy battle of World War II. Relive this momentous chapter in the war for the Atlantic, an intense game of chess pitting Admiral Karl Donitz's wolf pack against a battered British Navy. It's a three-day showdown with unparalleled violence and unexpected outcomes that will turn the tide of the war.

The USS Harder, led by Commander Sam Dealey, sank multiple Japanese destroyers, rescued Allied operatives from capture in Borneo, and outmatched many rival ships and aircraft to return home. And that was during just one patrol. Take a deep dive aboard this submarine as we relive this incredible war patrol in the spring of 1944, and witness the events that accelerated the campaign against the Japanese and earned Dealey the Medal of Honor.

Submarine commander Dick O'Kane participated in the most successful attacks on Japanese ships during World War II, until his luck, and the last torpedo he fired, took a dramatic turn. We track O'Kane's successful career, first as a protege aboard the legendary USS Wahoo, and then as Commander of the short-lived but lethal USS Tang. Through expert testimony, we relive O'Kane's seminal triumphs, and the tragic path of his last warhead.