The Koga will take you to your destination, by means of the capital of the land you want to reach. There is no cost, but you will have to sit on the floor, due to the low maintenance needed to keep costs down.
There are two Kogas: one that does a three-destination loop between North Hurnscald, Nivalis and Tulimshar, and the other shuttles between Candor and South Hurnscald.
The two Kogas are very similar, where they both have a place for refreshments, a place to rest, and slot machines for you to play for entertainment purposes.
This is the only Ferry (Koga) between Candor and Hurnscald.
Hurnscald North will take you to Nivalis, then Tulimshar.
Hurnscald South will take you to Candor.
Tulimshar Koga will take you to Hurnscald.
Nivalis Koga will take you to Tulimshar.