When you get the boat, go to the dock near Seahaven. Go to the Deathmarker Atoll. You will see three islands with a statue on each. Talk to the first statue. then to the last statue. Then the second statue. The the first statue agin. Cinematics after the Isle of Mists will play. Then you can go to the Ruins of Agalla without completing the Bloodmists Isle quests. you can gain exp from the two caves in the sea near stormhaven.