Instructions
Fly or walk to Westfall from Stormwind. Find Westfall by following the road west out of Stormwind.
Head south once you reach Westfall until you come upon the southern coastline.
Swim south while keeping as much distance between you and the coastline without becoming fatigued. If you swim too far away from the coastline, the fatigue status bar will display and you must then swim closer to the coastline.
Swim until you reach Booty Bay. It will take you roughly 20 minutes to reach the Booty Bay dock. Once there, climb the dock ramp up into the city.
Wait at the dock until the boat to Ratchet arrives, and then climb aboard.
Leave the boat once it docks at Ratchet. You have now arrived at your desired destination.