Short Okinawa Trip in Jan/26 – Tips?

Hi! My wife and I will be in Okinawa from Jan 13 (arriving 5PM) to Jan 16 (leaving at noon). It’s a short trip, so we want to make the most of it.

We’re thinking of staying in Onna and renting a car. We’d like to explore the north of the island, visit the Aquarium, and maybe go whale watching if that’s realistic for our timeframe.

Any recommendations for must-see spots or good places to stay this time of year?

Thanks!