Search the Wreck of the Vanguard in Jade Forest for clues about its cargo, and recover the Encoded Captain's Log.
Alright, soldier. I've got a critical mission for you. Get down to the coastline south of here - in the cove there you'll find a wrecked Alliance vessel. I need you to search it and find out if it was the ship that was carrying Anduin. Then, recover the Captain's Log and see if it has any information on where we can find him. Since the log is from a military ship, it'll be written using a cipher - take it to Nodd Codejack afterwards. He's keeping watch on the wreck from the other end of the cove.