After the discovery of mysterious fishing charts, Deadliest Catch captain Josh Harris turns to veteran fisherman Sig Hansen to learn more about the time his late father, legendary Bering Sea crabber Phil Harris, spent fishing in Hawaii decades ago.

Josh, Casey and Jeff travel to the southern edge of Kona's fishing grounds, where Phil Harris frequently explored. Despite the rough waters and unpredictable weather, the trio dives into the shark-inhabited waters to learn why Phil kept coming back.

Josh and his crew get an opportunity to supply ahi and mahi to a local restaurant and hope Phil's notes will lead them to a big payday. It's their first chance to turn a profit but if they want to succeed, they must first learn the Hawaiian way.

On Hawaii's Big Island, Josh enlists the help of Johnathan Hillstrand to help him dive deeper into the mystery of Phil's charts and gain insight into the time Phil spent in Kona Town.

Inspired by Phil's love of history, Josh, Casey and Johnathan Hillstrand brave unknown waters in the dead of night to try their hand at the ancient Hawaiian Ika-Shibi fishing technique.

With only two days left before they must head back to Dutch Harbor for King Crab season, Josh and Casey have one last goal to achieve in Hawaii -- land a big marlin, the one fish that eluded Phil Harris decades ago.