After you get the boat for real (when you return the GEM/eye to the temple just up from the Vikings) you head to the tower at the top of the map and that is what you have to do to accomplish his goals, I would advise some exploration and leveling first though. As an aside if you have a monk go down the bottom of the map and just right of the center (where there is a tree floating around the desert) there is a village head to the uppermost house and enter the fireplace in a pot there is a nice claw and some decent items in the chests, I also advise raiding the castle just down and left from the tower you have to go to