Drain the Oceans - Season 4

Hollywood's version of the Wild West is pure fiction. So what was frontier life really like? The wreck of a 19th-century steamboat yields case after case of expensive Champagne; the Little Bighorn battleground sheds light on the nature of General Custer's defeat; and a crumbling Californian mining town reveals a major part of its society is almost forgotten.

The largest treasure ever found underwater makes headlines worldwide, but soon, attention turns to who really owns the half-billion dollar treasure of the mysteriously code-named 'Black Swan'? Fearing one of their most prized historical treasures has been uncovered, the Kingdom of Spain takes on salvage company Odyssey Marine Exploration for the treasure. As the two sides fight it out in a Tampa court, it soon becomes clear that not all is what is seems...

The Arctic: a Cold War battleground hiding remarkable secrets. ‘Camp Century' was like something out of sci-fi: a US Army base under the Greenland ice cap. Lost and forgotten for 50 years, climate change may bring the camp and its dangerous waste back to the surface. While deep beneath Arctic waters is the ghostly wreck of a long sunk Soviet nuclear submarine that may be leaking radiation. Cutting edge science teams take on these toxic legacies.

This unusual and surprising episode about the archaeology of film making addresses one big and fascinating question. During the tumultuous decades of the 1920s and 30s, amid the greatest financial crisis in history, how did Hollywood capture the world's imagination and establish one of America's most successful industries?

At the end of the last Ice Age, the first humans migrated into the Americas. Some believe they travelled overland, but now archaeologists are looking to the coast. And what does a 13,000-year-old skeleton found in the Mexican jungle tell us about these people and their world? By draining ta deep, underground cave, we reveal the new science rewriting the epic story of the first humans to live in the New World.

Once known as Queen of the Adriatic, Venice conquered the eastern Mediterranean, but how did her fleet enable her to become a maritime empire? The wreck of a 14th-century war galley uncovers Venice's naval secrets; the wrecks of merchant ships reveal how Venice became an economic powerhouse; and how mass graves uncovered on a Venetian island show Venice faced an enemy which even she couldn't conquer.

From a steamboat in a cornfield to the true story behind Hurricane Katrina's floods, new discoveries reveal how the Mississippi river shaped America.

From the earliest colonization attempts to now, hurricanes have wreaked havoc along the North American coast. Exploring the wreckage reveals surprising truths about the continent's history. Through the remnants of a 16th century Spanish galleon, a mysterious pile of revolutionary era cannons, and hundreds of submerged New York subway cars, scientists are uncovering how hurricanes have shaped America's past - and how they might impact its future.

What secrets lie beneath the waters of the world's largest coral reef? Dive the SS Yongala, a passenger/cargo ship sunk in 1911 during a cyclone, and the HMS Pandora, sunk in 1791 after striking the reef with captured mutineers from the HMS Bounty. Also, follow an expedition to map the reef and explore its geologic history

A sea of secrets, myth, legends and great empires, ships have sailed the Black Sea for millennia. Its deepest waters is devoid of life, preserving shipwrecks that provide a window into its rich history. Draining the Black Sea unlocks secrets of an ancient ghost of the deep; how a naval fleet was pulverized in just 30 minutes; and will also reveal the final resting place of Hitler's lost U-boat.