Chuuk, one of the four states of the Federated States of Micronesia, is best known for its vast lagoon which is one of the largest enclosed lagoons in the world. But what sets Chuuk apart is what lies beneath those calm blue waters: an entire underwater fleet of sunken warships, aircraft, and submarines left from World War II. Often called the "Ghost Fleet of Truk Lagoon," these wrecks make Chuuk a global destination for experienced divers.