Dr. Robert Ballard of Woods Hole Oceamographic Institure and his research team become the first undersea explorers to locate, photograph, and explore the wreckage of the ill-fated HMS Titanic, which sank on its maiden voyage 2 1/2 mile deep in the icy waters of the Atlantic in 1912, taking 1500 passengers and crew with it to a watery grave. Utilizing dazzling state-of-the art equipment and cutting edge expertise they record the decaying remains of the ocean liner once thought "unsinkable."