Koh Bon dive site
Koh Bon is part of the Similan Islands national park but is located about 40 kilometres north of the Similan Islands proper. It’s an uninhabited limestone island that attracts divers because it is the best place in Thailand to dive with manta rays.
The most popular dive at Koh Bon is on the plateau which stretches out from the west ridge. On a day with mild currents you can drop directly onto the plateau, but normally strong currents require you to start in the south bay and swim out along the wall first. The wall is beautiful (great for a night dive), covered in sea fans, sea whips and zigzag clams. You can see various moray eel species, cuttlefish are pretty common. But most divers are focused on seeing mantas further out.
If the manta rays come to play you don’t need to chase after them, they are much faster than you. Just hang steady and they’ll keep circling round.
How to dive Koh Bon
You can dive the Koh by day trip from Phuket or Khao Lak, or by liveaboard. Liveaboards are ideal given the distance from the mainland.
If you don’t mind longish transfers then Koh Bon diving day trips with 2 dives run on Wednesdays and Sundays from Phuket.
Koh Bon is park of the Similan Islands national marine park and the diving season is from 15 October to 15 May.