For those who have not completed games in the Xenoblade Chronicles series, this page contains spoilers regarding the plot. Discretion is advised.
The Ancient Ship (Japanese: 古代船, Kodai-sen) is a story-exclusive area in Xenoblade Chronicles 2. It is located in an uncharted region of Alrest. It is impossible to return to the Ancient Ship after Chapter 1.
The Ancient Ship was sank beneath the Cloud Sea by Addam with Pyra on board in an attempt to seal away the power of the Aegis. Five hundred years later, Torna would lead the young salvager Rex there to get to the Aegis, due to the boy's Leftherian blood. The plan failed however, when Rex awakened Pyra and escaped Torna's clutches.
Landmarks and Locations
Despite being explicitly told by Spraine that Rex is unable to reboard the C.S.E.V. Maelstrom, it is possible to Skip Travel back to Argentum Trade Guild with Nia, Malos, and Jin. This also allows the characters to use different lines, such as resting at the Lemour Inn.