Naha and Miyako or a different Island?

Hi all! I am heading to Naha for 3 days in early April and was thinking of either heading to another island (thought of Miyako) for other 2 full days or stay in Naha and ferry to other islands. Which Okinawan island would you recommend in my case (and the time of year)? For me beaches and snorkeling are good, but also really into culture if there's an island that offers more of it.

Thanks!