One often thinks of Okinawa as a set of idyllic tropical islands with white sandy beaches and blue waters, so visitors to the main city of Naha are often surprised to find how large it actually is. Just getting to the popular Churaumi Aquarium on the northwest coast takes at least two hours by driving from Naha City in the southwest coast - this is not an island you can stroll around in. Visitors who want to explore the island properly are highly recommended by the tourism authorities to hire a car to maximise their travel time.
So, imagine my disappointment when I realized that I didn't have the right licenses to rent a car in Japan. My local driving license was not sufficient and the rental car companies required an international driving permit on top of that. But, you can still get around the island by public transport on your own. You'll just need to be a little more careful in planning your time.
The Yui monorail system is probably the best option when visiting downtown Naha city. It is easy to take, frequently arrives every 10-15 minutes. It connects several key tourist attractions in the city from Naha airport, like Kokusai shopping street, Okinawa Prefectural Museum, and Shuri Castle at the far end, with plans to extend the line in the near future. Yui Rail has even published a helpful English guide to show all of the tourist attractions that one can access from the monorail; useful for tourists exploring the city.
Single trips on the monorail will cost between ¥110 to ¥300, depending on distance. For those planning to visit more than one location in a day, consider the 24-hr or 48-hr pass for just ¥700 and ¥1,200, respectively. If you are strategic about it, you can maximize travel time.
For getting around the island itself, there is quite an extensive bus network on Naha. You may have to spend some time figuring out bus schedules and timings, but that can be easily done online at Busmap Okinawa. From Naha City to the northern end of the island, travel time is at least 2-3 hours. So, plan to wake up early and spend an entire day out. Or, if you can, plan to stay overnight to maximize your visit. Bus stops are marked quite well and usually have the time schedules posted at the bus stop for reference. Be sure to note the timings as you may have to wait up to an hour for the next bus if you miss it.
If you are traveling in a small group and can split costs, a taxi might not be a bad option for some flexibility. But, it does cost quite a bit more as the bus ride from Naha city to Churaumi Aquarium is just under ¥2,000, even by express bus. A taxi will run approximately ¥15,000. Do note that traffic on Naha's roads can be quite heavy during peak hours, so you might not be saving very much traveling time either. You can find some taxi info here.