Seychelles Anse Severe

A not so well known beach (like Anse Source d'Argent), but still worth visiting.

I recommend a wide angle lens. It is also helpful to wear water shoes, which will allow you to move a little safer in the water and not hurt yourself on small corals or rocks.
Take your pictures during midday hours as the colors come out especially nice. Unfortunately, my month of travel (August) was not particularly good for this because there were often overcast skies/diffuse light. On top of that, the sea was rather choppy.

You can ride your bike directly to the beach and park it there. You will probably meet at least one of the giant tortoises there.