Crescent Isle (三日月島) is a small, uniquely shaped island off the coast of Nasr (Vyse becomes aware of this after he discovers red moon stones on the island) where Vyse becomes stranded after he was separated from his companions following the shipwreck of the Little Jack. The body of Gonzales is located here.
After becoming captain of the Delphinus, Vyse follows Gilder's advice and establishes a base on Crescent Isle. Vyse's companions and crew rest here between missions and while modifying the Delphinus. For a little extra money and the appropriate crew members, Vyse can fund the building of various structures, shops, and decorations for the base.
Note that the enemies on Crescent Isle only appear during certain events and in limited numbers. Grapors are only fightable while Vyse is stranded on the isle, while Shadows are fought during Ramirez's attack.
- Some speculate that Crescent Isle may become the permanent headquarters of Vyse's Blue Rogues following the game's conclusion.
- The Dreamcast "swirl" can be seen on the fountain at center of cresent isle after Kirala is requested to rebuild it as a "tribute to the moons".