You have a few public transportation options if you're heading to the Okinawa Churaumi Aquarium. The most convenient way is to take the super-fast Yanbaru Express Bus from Naha Bus Terminal—it'll arrive in around two hours. You can also try driving down the Okinawa Expressway or hopping on an Okinawa Bus. And plenty of local buses are running around Nago City to take you all the way there.