Ask the Boatman
Objectives
The Elder's friend sailed from the Palisade Islands, so you should start your search by figuring out where he sailed to. Speak to the Boatman in eastern Archosaur.
Other stages
Conversations
Yes, long ago there was a person who returned from the Forbidden Sea. I'm not sure where he eventually went, but he probably did not travel far. Go ask the Fisherman north of Mount Lantern.
Okay.