Is my Osaka → Zamami travel plan realistic?

Hello all! I have a big Japan trip planned for June–July and I’m trying to figure out my travel from Osaka to Zamami.

I’m planning to take a flight from Kansai Airport (KIX) at around 9:30 AM, arriving at Naha around 11:50.

From what I’ve read, there are only a few ferries per day from Tomari Port to Zamami, with a high-speed ferry around 15:00.

In a worst-case scenario, is it realistic to land in Naha, get to Tomari Port, and make that 15:00 ferry? Or is that too tight?

Thanks in advance!

by freezebrotha