Underwater, meanwhile, all sorts of marine creatures have helped establish the reefs and the sandy beaches. When you climb up to Sailing Boat Rock, consider the brilliant white sand below.
This beach is in large part a product of diligent scraping and nibbling away by organisms such as the parrotfish - an average individual of which species may excrete more than 16 kilos of sand in the course of a year's lunching on hard corals. And there's plenty here to eat.
The conditions for coral growth are ideal, with a minimum prevailing sea temperature of about 28oC and exceptionally clear waters. More than 200 species of hard coral alone have so far been identified in this area, while these islands have the greatest profusion of reef fish in Thai waters.