Philippe and Ashlan Cousteau uncover new leads in the search for pirate Calico Jack's missing treasure that could be worth $250 million. Their mission reaches a stunning climax during their high-risk scuba dive beneath waves.

The Cousteaus search for lost Spanish treasure on South Padre Island, TX.

Ashlan and Philippe head to Roatan, Honduras, to investigate rumors of a lost chest of gold still missing on the island. Their mission combines moments of incredible beauty and harrowing danger as they try to solve the mystery.

Philippe and Ashlan Cousteau visit a private island off the coast of Belize to investigate a modern-day treasure map. It could hold the key to unlocking a pirate secret shrouded in mystery for hundreds of years.

The Cousteaus risk their lives to explore an unsolved family mystery.

The Cousteaus search for an infamous pirate's lost treasure on St. Croix.