Watch history unfold as the wood-hewn sailing warships of the 18th century give way to the iron-hulled steamers of the 19th century. This episode will take viewers on a trip through time to learn how pivotal battles, and technological advances combined to make speed and firepower the driving force in the era of SEA POWER. By the U.S. Civil War, steam power and iron hulls were essential components for modern warship technology. Now was the time for firepower to take center stage in determining supremacy at sea. BIG GUNS examines the evolution of battleships from the 1870s through World War II. Take a revealing journey underwater with SUBMARINES. This mesmerizing episode opens with a look at the Turtle, a Revolutionary War-era submarine. From the first steam-powered subs to today's nuclear-powered, ballistic missile-equipped behemoths, SUBMARINES will open your eyes to the power that lies beneath the seas. How do you maintain an airbase at sea? Find out in AIRCRAFT CARRIERS. This final WARSHIP episode tracks the challenging campaign to combine sea and air power into one lethally self-sufficient weapon.