There is no guarantee of seeing Manta Rays at Koh Bon, but they are reported to visit most days late in the diving season, especially from mid of January until April and May.
Koh Bon is located about 22km to the northeast of the Similan Islands’ northernmost point. There are no beaches here at Koh Bon, so visits are strictly for diving only. Unlike dive sites at The Similan Islands main archipelago, which are made up by granite rocks, Koh Bon is limestone.
The main dive site is on the southwest corner of the island, the ´Westridge´. A ridge that gradually goes deeper and deeper, well over 40 feet.