You have 3 minutes to lead Osh back to Nipik at Fina's Shrine ( -1572, -537, -2380 ) /waypoint -1572, -537, -2380. If you get too far from Osh you may leave him behind. If you don't get Osh back to Nipik in 3 minutes, you must go back to the sunken boat and speak with him again. (Flying him there didn't work).
Speak with Nipik
Watch the ceremony.
Speak with Osh.
Find Nipik at ( -1632, -502, -2275 ) /waypoint -1632, -502, -2275 and speak with him again.