The evolution from wooden ships to metal ones in the second half of the 19th century is examined.

The 200-year evolution of the submarine in wartime is examined, told by the designers and engineers behind the machines.

A chronological look at the events of the 1944 D-Day landings, and the vessels that made the invasion possible, with an insight into personal stories and engineering wonders.

A look at the smallest ships of war and the major roles they've played over the centuries, including the 1776 gunboat built to stop a British invasion and the HA-19 sub.

An up-close look at the naval carriers, destroyers, and nuclear submarines of the Cold War.

A look at some of the rescue ships of the past 200 years of wartime and the brave men and women who risked their lives to save others.

From tests in the River Thames, to the German's deadly U-boat attacks in World War II, this episode explores the silent threat of submarines.

A look at how the role of battleships changed over the course of the First and Second World Wars.

A look at the most famous wooden warships over the course of 500 years.

A look at how the art of deception was used by naval forces in the first half of the 20th century; in 1939, the German raider Atlantis is equipped with fake funnels, while its sailors dressed as women pushing prams to fool Allied merchant ships.

Before the advent of air transportation, trains played a vital role during times of war. In addition to transporting soldiers and supplies to the front lines, the locomotives served as mobile hospitals and were sometimes used as massive weapons on wheels. "Combat Trains" explores some of the machines and railways that helped change history dating back to the Civil War. The show uses archival footage and accounts from veterans to highlight the stories of engineering prowess that helped the soldiers do their jobs.

Stories of some of the greatest and deadliest submarine patrols of World War II.

A look at some of America's most important battles during World War II and the unprecedented innovation that occurred during the conflict that followed Pearl Harbor.

A team of experts travels through Europe's mountains, forests and industrial heartland to uncover a Nazi world hidden for decades and to unravel the stories of those who designed, constructed and operated Adolf Hitler's devastating weapons.

This series unveils the engineering secrets of various iconic megastructures that went on to spark a technological revolution, ultimately changing warfare forever. The Nazis built some of the biggest and deadliest pieces of military hardware in history. Adolf Hitler hired men like Wernher von Braun, Ferdinand Porsche and Alfred Krupp to build huge terror machines, high-tech superguns and weapons of mass destruction.

Follow the teams of engineers as they execute the world's most amazing moves. Each dangerous and daring relocation comes amidst tough conditions and extremely tight deadlines. These heavy haulers overcome incredible challenges to get their massive cargoes across land, sea, and air. These cargoes include some very fragile, massive, and expensive cargoes on the planet and lots of care is taken to see them to their final destinations.

"I have no problem sacrificing myself for someone else. It's my job." So says a member of the elite Combat Rescue unit of the U.S. Air Force, whose job it is to come to the aid of American or Allied forces who are either injured or are in extreme danger. "Inside Combat Rescue," the result of unprecedented access provided to National Geographic Channel, takes viewers inside the harrowing world of the brave airmen -- Pararescuemen or PJs, as they're known -- during a four-month deployment to Kandahar, Afghanistan. More than two dozen missions are chronicled in the series, using strategically placed cameras on airmen's helmets and more than 40 cameras mounted both inside and outside of the Air Force's Pave Hawk helicopters. PJs and their rescue teammates race against time to save Americans, coalition forces, Afghan allies and even local Afghan families caught in the crossfire within the "golden hour," the critical first hour that's often the difference between life and death.

A century after the war was fought, this five-part series explores whether or not World War I could have been avoided and how people endured the battles for four years. The program uses more than 500 hours of colorized, archival footage -- much of which has not been seen previously -- to tell the story of the worldwide conflict on a human level. Viewers are transported into the heart of battle -- in countries that include France, Russia and Palestine -- and inside the day-to-day lives of civilians behind the front lines.