Snorkelling beach closures/partial closures

Hi,

We're planning to go to Okinawa and the Kerama Islands in late October/early November this year. I've seen a couple of websites suggesting that popular beaches (Aharen etc.) have restricted swimming access to their 'best' snorkeling areas – does anyone know if there is an official list of beaches where this is the case and whether it is a permanent arrangement for these beaches?

A further question – I realise that beaches in the Kerama Islands close in November, as in no longer have life guards. Does this mean all the eating options and snorkeling gear rental shops also close?

Thanks in advance,

Ant