On the 100th anniversary of Titanic's sinking, National Geographic revisits the romance, glory, and tragedy of this tremendous ship and presents an insider's look at the new findings about the passengers and scientific study of the wreck site. For 100 years the great ship Titanic has rested in its final grave on the ocean floor, lost to deep ocean darkness until its 1985 discovery by National Geographic's Bob Ballard. Relive the spell-binding tragic final hours of the ship in a detailed retelling of the famous story and learn the personal stories of lesser-known passengers, including the "guarantees." For the first time since its discovery, Ballard travels to Belfast to interview descendants of the ship builders and the "guarantee group"--the ill-fated men who traveled on the ship's first voyage to assure its seaworthiness. Understand underwater mapping techniques that have brought Titanic's debris field into high resolution, and get a glimpse of current deep ocean scientific research on the wreckage and the future of underwater exploration.