Island hopping from Ishigaki to Yakushima

I would like to hope as much as possible from Island to Island by boat ferry. The start would be in Ishigaki and the end should be in Yakushima Island. Can you please let me know from what Island to what Island is a ferry around ?

Thanks very much Tobias

I guess the hardest part will be from one od the islands in Okinawa to Yakushima unless there are some ferries around that also stop on the smaller islands (unlikely). Its at least possible from the main island of Okinawa to Yakushima

When you google Okinawa to Kagoshima ferry, this is the first option...

https://www.aferry.com/kagoshima-naha/

https://www.visitokinawa.jp/transportation/ferries-to-islands

another option with links...

As far as I know there is A''LINE ferry from Naha (Okinawa main island) to Kagoshima.

https://www.aline-ferry.com

Unfortunately there seems to be no English page.

The route is Naha-Motobu (Okinawa main island)-Yoron (Yoron island)-Wadomari (Okinoerabu island)-Kametoku (Tokunoshima island)-Naze (Amami-Oshima island)-Kagoshima.

I think this is not "tourist-friendly" and you must behave as a local to endure the long trip.

I am afraid there is no direct boat to Yakushima from south. There are some ferries/high speed boats from Kagoshima to Yakushima though.