Japan, <a href="https://en.wikipedia.org/wiki/Okinawa_Prefecture" class="extiw" title="en:Okinawa Prefecture">Okinawa Prefecture</a>: clear seawater, near <a href="https://en.wikipedia.org/wiki/Tokashiki_Island" class="extiw" title="en:Tokashiki Island">Tokashiki Island</a> (Aharen Beach).
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/stephen-oung/">Stephen Oung</a>
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<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/stephen-oung/6081216280/">Original version</a>