Similan Liveaboard Trip Report 9-13 February 2025

Barracuda tornado, fish stampedes at Richelieu and a manta ray at Koh Bon – this was one of the best Similan liveaboard trips I’ve ever been on.

Manta Ray with only one cephalic lobe at Koh Bon, Similan Islands, Thailand in February 2025
Manta Ray at Koh Bon, Similan Islands, Thailand, February 2025 © chris@divehappy.com

I am not particularly lucky when it comes to scuba diving. How many times have I heard “ooh, you should have been here last week” when I’ve come back from a particularly uninspiring dive.

Longnosed Emperorfish stampeding over barrel sponge with glassfish, Richelieu Rock, Similan Islands, Thailand, February 2025 © chris@divehappy.com

So on this Similan liveaboard trip in February 2025 felt like I was finally getting payback for all my patience and near-misses in previous years.

Pook and the jacks, Richelieu Rock, Similan Islands, Thailand, February 2025 © chris@divehappy.com

To begin at the end, our final dive of the trip at Koh Bon delivered the best finale you could hope for – crystal clear visibility and a oceanic manta ray gliding in from the deep to hang out in Koh Bon bay, the easiest, most current-free spot on the entire dive site. (See more photos of the manta ray at Koh Bon).

The manta moment followed on from the awesome encounters we’d had over the previous couple of days.

Barracuda Tornado, Koh Tachai, Similan Islands, Thailand, February 2025 © chris@divehappy.com

Having already had an epic barracuda tornado on a December 2024 Similan trip, lightning struck twice and it happened again at Koh Tachai pinnacle. Hundreds of barracuda circling in perfect visibility at around 10 metres over Koh Tachai pinnacle – it just does not get any better. I’d had some awesome barracuda bait ball encounters before at Tachai (link to trip report with that photo) but this was on another level. (See more photos of the barracuda tornado at Koh Tachai).

Huge school of fusiliers running around Richelieu Rock, Similan Islands, Thailand, February 2025 © chris@divehappy.com

The following day at Richelieu Rock we had more crystal clear visibility which let us see the whole site laid out below us – and some amazing runs of massive schools of fusiliers thousands strong past the rock. Richelieu is notoriously fickle for viz so when it clears it makes it feel even more special.

Longnosed Emperorfish Stampede, Richelieu Rock, Similan Islands, Thailand, February 2025 © chris@divehappy.com

The long nosed emperorfish were also out in force stampeding over the rock too, flowing around the big barrel sponges and soft corals and any hapless divers that were in the way too.

Snapper and glassfish, Richelieu Rock, Similan Islands, Thailand, February 2025 © chris@divehappy.com

The glassfish are always at Richelieu Rock, millions of them like a protective silver blanket suspended over the reef. When the sun’s out they gleam over the coral and shape shift around the bigger fish speeding through

Pook and yellow snapper, Richelieu Rock, Similan Islands, Thailand, February 2025 © chris@divehappy.com

The resident big school of yellow snapper on the inside of the horseshoe were also super active and out en masse.

Jack Tornado, Richelieu Rock, Similan Islands, Thailand, February 2025 © chris@divehappy.com

Best of all though was the surprise of a big school of jacks forming into a tornado just off the rock out over the flat sandy bottom at 30 metres. While jacks are often seen at Richelieu, I’d never seen them in these numbers or behaving like this. It was even more a surprise after seeing the barracuda the previous day. (See the full set of jack tornado photos).

Longnosed Emperorfish stampede, Christmas Point, Similan Islands, Thailand, February 2025 © chris@divehappy.com

On the first couple of days of the liveaboard we enjoyed great dives at several of the Similans’ classic sites. At Christmas Point, amongst the labyrinth of big rocks out of nowhere there had been a stampede of long nosed emperor angel fish which caught us by surprise.

Fan corals and red rocks, Christmas Point, Similan Islands, Thailand, February 2025 © chris@divehappy.com

The viz was great at Christmas Point, the sun illuminating the red carpet of coral on the huge rocks shaped by thousands of years of water movement.

Pook with glassfish and soft corals, West of Eden, Similan Islands, Thailand, February 2025 © chris@divehappy.com

At West Of Eden, we got to enjoy a different perspective on the site as we dived it in the afternoon whereas we usually see it first thing in the morning as the beginning dive of a trip. There was a lot of activity at Eden and the ledge suffused with soft corals was buzzing with glassfish, making it even prettier than usual.

Huge barrel sponge and blue ringed angel fish, Ao Pakkard, Similan Islands, Thailand, February 2025 © chris@divehappy.com

As a pleasant calm interlude between the full on action at Koh Tachai and Richelieu Rock, the early morning dive at Ao Pakkard in the Surin Islands is always a pleasant bob along the reef.

Pipe corals and damselfish, Ao Pakkard, Similan Islands, Thailand, February 2025 © chris@divehappy.com

The hard corals here are in fantastic condition, with some huge barrel sponges, plenty of reef fish and coral upon coral piled upon each other.

Damselfish and staghorn coral, Ao Pakkard, Similan Islands, Thailand, February 2025 © chris@divehappy.com

The site is shallow and usually without any current, so it’s a perfect start into the day before heading to Richelieu.

Rainbow runners, emperorfish and trevally running together, Richelieu Rock, Similan Islands, Thailand, February 2025 © chris@divehappy.com

Incredible to get this variety of experiences and encounters within a four day liveaboard trip. It turns out that if you keep showing up you do actually get to win – sometimes.

Fusiliers over the top of Richelieu Rock, Similan Islands, Thailand, February 2025 © chris@divehappy.com