New discoveries reveal the treasures of a ghost fleet of Japanese ships at the bottom of the South Pacific in the Chuuk Lagoon, also known as Truk. Using cutting-edge underwater technology, experts are investigating a top-secret superweapon that could have changed the course of World War II.

At the bottom of Lake Erie, a mysterious shipwreck could be the oldest wreck in America's most notorious ship graveyard, the schooner Lake Serpent. Experts investigate new leads in this 200-year-old cold case using cutting-edge underwater archaeological methods.

When the SS Justicia, a sister ship of the Titanic, gets embroiled in war with a hidden enemy, the former luxury liner is sent to the bottom of the ocean; new discoveries and cutting-edge underwater technology might finally reveal the secret history of its sinking.