A memorable encounter with an oceanic manta ray at Koh Bon on a Similan Islands liveaboard trip in February 2025
Manta Ray at Koh Bon, Similan Islands, Thailand, February 2025 © chris@divehappy.com
Koh Bon is a famous hotspot for seeing manta rays in Thailand, but it’s definitely not a guaranteed thing. If anything, manta sightings at Koh Bon have got rarer in the 20 years I’ve been diving the Similan Islands. The last time I saw a manta here was three years previously in March 2022.
Manta Ray at Koh Bon, Similan Islands, Thailand, February 2025 © chris@divehappy.com
So when a manta ray gets spotted at Koh Bon it’s a cause for celebration, even if it’s just a fly by. The dream scenario of course is for the manta ray to arrive near the beginning of the dive and not to be caught in the strong currents that sometimes pass through Koh Bon.
Manta Ray at Koh Bon, Similan Islands, Thailand, February 2025 © chris@divehappy.com
On our February trip, wishes were granted. A manta ray had been spotted by other boats during our surface interval before the final dive of the trip. The sun was out and the visibility was awesome – perfect conditions for scanning the blue to see if we could spot the silent manta.
Manta Ray at Koh Bon, Similan Islands, Thailand, February 2025 © chris@divehappy.com
Usually manta rays are seen at the end of Koh Bon ridge, down at about 20 metres where they like to circle around. However, that same area can get some strong currents that whip around the ridge, which can make it hard not to get blown off the dive site.
Manta Ray at Koh Bon, Similan Islands, Thailand, February 2025 © chris@divehappy.com
Once we’d gone in, we started off in Koh Bon bay, the area of calm water away from the currents from where you progress out along to the ridge. But we had the greatest luck of all – we barely had to move anywhere when the oceanic manta ray, all three metres wide wingspan of it, came gliding in from the deep. Everyone was hovering at around 10 to 15 metres so it was the perfect depth to sit and observe.
Manta Ray at Koh Bon, Similan Islands, Thailand, February 2025 © chris@divehappy.com
This wasn’t just a fly by either – despite there being 30 or so diver in the water quite spaced out across the bay, the manta patiently sailed around us, seemingly inspecting who we were and what was going on. It certainly wasn’t shy of getting close to me.
Manta Ray at Koh Bon, Similan Islands, Thailand, February 2025 © chris@divehappy.com
The manta made a few large loops at a stately pace around us, seemingly disappearing only to come back and come up close. We had a good 10 minutes or so before the manta ray unhurriedly headed back out into the blue.
Pook and Manta Ray at Koh Bon, Similan Islands, Thailand, February 2025 © chris@divehappy.com
Sadly, the manta was missing one of its frontal cephalic lobes, but it seemed completely unbothered by it. That’s also made it very identifiable, so we will be hoping to see it again next season.
Thanks to my veteran dive guide Ric Parker, the underbelly pics from this encounter have been uploaded to Manta Matcher and now we can see if this manta gets seen again. It seems like this is the first time it’s been seen according to the database.
Recommended Similan Liveaboards October 2025 to May 2026
Blue Dolphin Liveaboard
A mid-range liveaboard with 7 cabins for 16 people. Check availability and pricing
The Phinisi Liveaboard
A Similan mid-range liveaboard with 7 cabins for 18 people.Check availability and pricing
Smiling Seahorse Liveaboard
A mid-range liveaboard with 8 cabins for 16 people. Check availability and pricing
The Junk Liveaboard
A mid-range liveaboard with 6 cabins for 18 people. Check availability and pricing
This was all part of an epic Similan liveaboard trip in February 2025 where we had an amazing run of luck – not just the manta ray, but a barracuda tornado at Koh Tachai and a jack tornado at Richelieu Rock, among all sorts of other stuff. See the full trip report.
Pook and Manta Ray at Koh Bon, Similan Islands, Thailand, February 2025 © chris@divehappy.com
2025 Thailand Last Minute Liveaboard Deals
- Thailand Aggressor - 30 Aug 2025 - from €2,260.00 - South Andaman Sea (Chalong - Chalong) - Travel the World Special! (25% OFF)
Similan Islands Dive Sites List
- West Of Eden
- Shark's Fin Reef
- Boulder City
- Christmas Point
- North Point
- Three Trees
- Tuna Wreck and Hideaway Bay
- Koh Bon
- Koh Bon Pinnacle
- Ao Suthep
- Richelieu Rock
Similan Liveaboards Overview
- Luxury Similan Island Liveaboards
- Mid Range Similan Island Liveaboards
- Budget Similan Island Liveaboards
- Last Minute Liveaboard Deals
- Diving The Similan Islands 2025: A Quick Guide
- Similan Islands Dive Sites
- Diving Thailand Guide
Upcoming Similan Liveaboard Availability and Pricing
Check availability and pricing for all Similan Islands liveaboards departing in
- October 2025 | November 2025 | December 2025 | January 2026 | February 2026 | March 2026 | April 2026
(The Similan National Park is closed from mid May to mid October each year)
Similan Liveaboards Trip Reports
Photos from each of the Similan liveaboard trips I've been on over the years.
- Similan Islands Liveaboard Trip Report 9-13 February 2025
- Similan Islands Liveaboard Trip Report 21-25 November 2024
- Similan Islands Liveaboard Trip Report May 2024
- Similan Islands Liveaboard Trip Report 21 - 25 February 2024
- Similan Islands Liveaboard Trip Report 15 - 19 February 2024
- Similan Islands Liveaboard Trip Report December 2023
- Similan Islands Liveaboard Trip Report October 2023
- Similan Islands Liveaboard Trip Report April 2023
- Similan Islands Liveaboard Trip Report February 2023
- Similan Islands Liveaboard Trip Report December 2022
- Similan Islands Liveaboard Trip Report February 2020
- Similan Islands and Myanmar Trip Report March 2015
