Okinawa (Ishigaki) in late october

Hi guys
Me and my wife are planning honey moon in Okinawa. We would like to go around 20/25th of October to Kabira, Ishigaki.
Our concern in the weather condition specially sea. We�fve been warned in travel agency that sea might be cold and presence of jellyfish can be a big problem.
However, I read somewhere that till December water in sea in warm. We are confused now and don�ft know what to do.
Regards
Mario

The water temperature around Ishigaki is usually around 26 degrees in late October. Most people consider that warm.

The air temperature is typically around 28 degrees during daytime and 23 during nighttime. Most people consider that warm, too.

It is also a relatively sunny period of the year (for Okinawa standards) with typically around 33% rainy days and 50% sunny days.

Even though water in sea is warm , the air is a little cold.
In October, some tourists swim in the sea.
Native people don't do it.
You can swim in October but it might not be comfortable.

We were staying in Ishigaki last week and the water temp. up around Kabira was about 28C. We stayed in Ishigaki City and just did day tips around the island. There are so many beautiful little isolated beaches dotted around the NW and N parts ofthe island. One day we spent all day at 2 different beaches up near Club Med and never saw another person! There were beach reefs immediately off the beach for snorkelling. It really is a beautiful place.

I can't imagine the water temp. dropping too much by the end of October bearing in mind the waters are fed from the warm Kuroshiro current from near the equator.