Fiona Powell is an explorer for National Geographic, whose scientist father disappeared while investigating ancient shipwrecks. She dives in search for clues on the very sunken boats he was studying, hoping to find a lead to his trail.
Nat Geo Adventure: Ghost Fleet is a straightforward hidden object game with a sea exploring theme and mini-games between each location. The available shipwrecks are shown as pins on a sonar screen, where the player must click on sections of the open sea to activate the probing signal and reveal their positions. The pins give access to one of the underwater scenes filled with assorted junk and other paraphernalia, where the objective is to find and click on all the items listed at the right side of the screen. A PDA with historical notes about the ships visited can be accessed at any time from the bottom interface, with tabs for crew profiles and information about the artifacts found on the sites.
List entries in yellow are stored inside the inventory after being collected from the wreck. They have to be used on certain shining hotspots, to perform an action or complete a task. In some cases, the necessary tool might be hidden on a different sunken ship, and the player must go back and forth between the locations to complete the scenes. The hint button darkens the whole screen, leaving only a small spotlight circle showing the position of one of the required objects. Extra hints can be found and collected from the scenery as ? symbols. Collected artifacts unlock bonus content, like wallpapers and screensavers.
The mini-games are implementations of old concepts: jigsaw puzzles, scrambled pictures, a spot-the-differences game with two similar photographs, a memory game where the player must select pairs of cards, a variation of the "three shifting cups with a hidden stone" classic using oysters and a pearl, a Pipe Dream clone with twisted circuits that must be connected to disarm a bomb, and other similar challenges.