Back to Chapter 2
After finding the shipwreck in Flotsam you were told to search for more shipwrecks further up river in the Pontar Valley. The Shipwreck (#1) in this area can only be discovered right at the end of Chapter 2, during The Siege of Vergen quest.
Loot the chest in the ship to find the Vran Armor Enhancement and the Journal of Eyla Tarn. Once you loot this chest the quest will be complete.