Go to Captain Karith at the eastern boat in Yalahar and ask him for a passage. You must give Karith 5 items of your choice (out of 8 possible) to prove that traveling to other cities will be worth while. It is possible to buy these items needed before traveling to Yalahar. After collecting the items you must then name the city from which you acquired the item. The items do not need to be handed in at once.
Location of all the required items (You only need 5 of them)
After giving him 5 of the required items he will now activate the boat traveling routes to and from all the cities listed in the above picture.