The sea floor is the world's biggest tsunami machine, and its dangers have remained hidden from view -- until now.

In maritime warfare, saboteurs are a silent and unseen enemy.

Undersea empires and relics of their bloody wars lie beneath the waters of the world.

Ships sunk by the Japanese Imperial Navy.

Underwater secrets of ancient Egypt, Loch Ness and the California Gold Rush.

The secrets of lost ancient civilizations come to light when the Mediterranean is drained.

War, weather and human error have led to some of the worst maritime disasters in U.S. history.

Submerged shipwrecks and subterranean secrets reveal the story of New York City's rise.

Draining the ocean reveals a Basque galleon trading in whale oil; the Spanish empire relies on ships like this one to bring back valuable cargo; draining an Armada wreck off the coast of Ireland reveals a battle for control between Spain and England.

Malaysia Airlines Flight 370 goes missing, resulting in the longest, most costly search in aviation history.

Draining the Nile reveals lost secrets of the ancient Egyptian world.

Draining the ocean reveals the Gulf of Mexico's most deadly secrets.

The Ring of Fire is an area in the Pacific Ocean where volcanoes, earthquakes and tsunamis form; the ocean is drained to reveal the geological forces behind natural disasters and to uncover threats along the coast of Seattle, Tokyo and New Zealand.

The China seas are the most fiercely contested and mysterious waters on the planet.

The hidden secrets of the Nazis are revealed when the oceans covering them are drained using CGI animation.

Stories of clandestine missions conducted beneath the waves have remained hidden from prying eyes for decades, until now.

Pirates, gangsters and other villains have been swallowed up by the sea; cutting-edge technology reveals the secrets of the sea floor and exposes the shaky ground on which humans live.

Exploring evidence of underwater cities, which may be ancient archaeological sites or accidents of geology.

Draining the oceans reveals wrecks awaiting treasure hunters.

The story of how Rome dominated the world for 500 years by conquering the sea.

The plug is pulled on Scotland's famous lake to solve one of the world's greatest mysteries -- the identity of the Loch Ness monster.

From the award-winning team of filmmaker Darren Aronofsky ("Black Swan") and producer Jane Root ("America the Story of Us"), this 10-part cinematic event series explores the fragility and wonder of planet Earth -- one of the most peculiar, unique places in the universe. Host Will Smith guides viewers on an unprecedented exploration, bolstered by an elite group of eight astronauts who provide unique perspectives and relate personal memoirs of the planet seen from a distance. Hourlong episodes delve into monumental events such as genesis, cosmic violence, human intelligence and alien life, oxygen, and survival vs. destruction.

Actor Kal Penn is producer/host of a series that attempts to explain how things like money, sex, food, sports and crime influence daily lives. The consequences are shown by analyzing data maps, and episodes investigate different themes through data mapping, creative visualization of information and in-depth personal stories involving fascinating characters. As well, documentary vignettes tell stories that personalize the number crunching, introducing real people who live and work at key intersections of each theme being explored. Penn serves as guide, making the information relatable to viewers.

Oscar winners Ron Howard and Brian Grazer put their storytelling acumen to work as executive producers of "Breakthrough," a series of hourlong documentaries highlighting the stories, people, and technology behind the world's most cutting-edge scientific innovations. After considering more than 100 scientific topics for the series, the pair -- helped by National Geographic archives and research, along with the scientific resources of partner GE -- selected biotechnology, neuroscience, anti-aging technology, alternative energy, water conservation, and global pandemics. Each episode is directed by a prominent Hollywood star -- Howard himself helms "The Age of Aging," joining actors Angela Bassett ("Water Apocalypse") and Paul Giamatti ("More Than Human"), directors Peter Berg ("Fighting Pandemics") and Brett Ratner ("Decoding the Brain"), and screenwriter Akiva Goldsman ("Energy From the Edge").

Sir David Attenborough narrates this critically acclaimed series that dives deep into the marine environment of Planet Earth. Although two-thirds of the world's surface is covered with water, scientists know less about the oceans than they do about the surface of the moon. This limited series travels from various coasts to the poles to examine watery denizens ranging from the gigantic blue whale to microscopic coral polyps.

How did we get here? How did humankind evolve from apes swinging in trees to astronauts walking on the moon? National Geographic's eight-part time-travel adventure series delves deep into history to highlight pivotal "origin" moments that fundamentally and irrevocably created modern living. Host Jason Silva ("Brain Games") guides viewers through a dazzling audio-visual portal to explore these events, such as the discoveries and applications of fire, medicine, money and transportation, while experts across each field inject commentary. The series also incorporates scripted storytelling and documentary sequences.