Diving in the Similan and Surin Islands (2026 Liveaboard Trip Report)

What’s it like to go diving in the Similan and Surin Islands on Thailand’s Andaman Coast? Let me tell you all about it. Today I’m going to take you on an adventure through the crystal clear waters of the Andaman Sea, onboard the MV Blue Dolphin. 

Welcome to my 2026 Season Similan Islands Trip Report. I’ve been extremely lucky to be able to go diving in the Similan and Surin Islands two years in a row now, and I really hope it’s somewhere that I get to keep visiting for years to come. 

Need more inspiration for your trip? I’ve shared 20 photos from my trip, you can find that post here.

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Boat & Crew

I did a full review of the MV Blue Dolphin last year, so if you want a deeper dive into the boat, you can find that here. During the off-season they made improvements to the boat which meant this year there was even more incredible attention to detail that just helped make the trip even more comfortable.

The Blue Dolphin is a 25-foot steel hull boat with space for 16 guests. It has three decks; the lower deck, main deck and upper deck. The lower decks have the cabins, kitchen and diving area. On the main deck you have a large dining area and an air-conditioned hangout room. Then you have the upper deck, which has lounge chairs and a large table to gather for sunset drinks. 

While the boat was built in 2017, it was refitted in 2021.

I don’t even know where to start with this crew. They are easily the reason why I would do this liveaboard again and again. The general manager, Boots, has done an excellent job of bringing together the best people for his team. Not only did everyone remember us from last year, but they immediately made us feel like a part of the family. 

P. Anne cooks up the best food in the tiniest kitchen on the sea. Rat and Bua make sure you have everything you need, from snacks to hot towels and cold drinks after every dive. The dingy drivers Top and King pick you up with a smile after every dive and the engineer Pa is seriously the sweetest man on the planet. I’ve never seen someone smile as much as Yeee who’s in charge of filling our tanks, and the captain P Num is always making sure we arrive at each dive site safely. 

The dive crew have become some of our closest friends. There’s not only a high level of professionalism on this boat, but there is so much joy and fun on every trip. 

Itinerary & Dive Sites

Now for the fun part, the dives! We did a total of 14 dives over the four day trip in the Similan and Surin Islands. I’m going to share the highlights and my favorite dives from the trip. Since we came last year, I thought all of the dive sites would be ones we’ve been to before, but we actually had the chance to do different dive sites this year. 

If you want to read about the highlights from my trip last year, you can find that trip report here. 

Elephant Head Pinnacle

This was a new dive site that we didn’t do last year, and I would classify this as an ‘Adventure Dive.’ We needed a depth finder to help us get to the dive site and then once the dingy’s dropped you, you had to quickly descend to a deep pinnacle. This was such a cool dive site. There were boulders covered in soft corals, sponges and hard corals. 

On the way down a small school of tuna passed in front of us. I’ve never seen schooling tuna before, this was very cool. Around the dive site there are several swim throughs to explore. We also saw huge angelfish, tiny nudis and fish in general everywhere. I loved the top of the pinnacle, but because it’s a deep site, we couldn’t hangout for too long exploring. 

With a max depth of 32.7 meters and an average depth of 19.9 meters, this is definitely a dive you’re going to want nitrox for. 

Koh Tachai Pinnacle

Koh Tachai Pinnacle was easily my favorite dive site of our trip last year, and this year it didn’t disappoint. On this trip we did two dives at Koh Tachai Pinnacle with a max depth around 26-27 meters for both dives. Trust me when I tell you that you are going to want to have a nitrox certification on this liveaboard. 

What I love about Koh Tachai is the schooling fish and come together to hunt around the dive site. On our first dive there was a feeding frenzy of trevaly, long-face emperor fish and rainbow runners. We also saw a school of filefish, schooling barracuda and dog tooth tuna. This dive site always feels so fishy. 

Our second dive had fewer other divers and better visibility. Our group spread out to explore the reef surrounding the pinnacle and I loved looking for big lobsters, tiny boxfish and eels. We even saw a massive eel swimming through the coral garden. 

I will say on the trip after ours, they saw an oceanic manta at Koh Tachai! So this is definitely not a dive site to skip. 

Pak Kaad

I loved this dive site so much. Pak Kaad is so chill and the coral reef is absolutely stunning. If you’ve ever met me, you’ll know that you can stick me in six meters of water above a gorgeous colorful reef and I’ll be happy for hours. Out in the sandy bottom you can often have stingrays swimming around you, tuna passing by, schooling barracuda and trevally and long-face emperor fish hunting. 

This was also the dive where we got to see Harlequin shrimp for the first time! Check out a photo of these unique critters taken by our talented friend Frankie. They were so colorful, and much bigger than I expected.

I honestly just loved drifting over the coral reef at the end, searching for unique anemone fish and interesting nudibranchs hanging out on the coral. Our max depth was 19 meters with an average depth of 12 meters, so you can tell it was a very chill dive. 

Richelieu Rock

This year, I think Richelieu Rock was my favorite dive site of the trip. It’s a busy dive site, but we had absolutely incredible conditions with fish absolutely everywhere. Richelieu Rock is easily the most famous dive site in Thailand, and for good reason. 

The pinnacle itself penetrates the surface at low tide, and drops to depths around 30 meters. You can have strong currents, but if your guides know what they’re doing, they’ll take you around the hide from the worst of the current (and other divers).

This dive site has fish everywhere. Glass fish absolutely surround the pinnacle, interesting nudibranchs, seahorses and shrimps call this reef home while larger hunting fish parole at all times. 

Our final dive at Richelieu Rock was probably my favorite dive of the trip. A huge school of rainbow runners, trevally and long-faced emperor fish started hunting around the pinnacle, making for an exhilarating moment where I couldn’t even see my dive buddy through the wall of fish swirling around us. 

All three dives had a max depth of about 27 meters with an average depth between 15-18 meters. 

Safety Considerations and Dive Conditions

I’ve been very lucky to have excellent conditions both times I’ve gone diving in the Similan and Surin Islands. This year we had crystal clear visibility, calm seas and sun every day. As someone who takes photos exclusively with natural light, this is very important to me. 

As always keep in mind that the ocean is ever-changing, so the conditions on your trip might be different to mine. 

General conditions diving in the Similan and Surin Islands

• Visibility: We got lucky with amazing visibility on our trip. We had visibility between 15 and 30 meters on all of our dives. At Richelieu Rock we got especially lucky with visibility of 30-40 meters. 
• Water temperature: The average water temperature on our trip was between 29-30°C. I am always grateful to be wearing my long, 5mm wetsuit, but I didn’t need to wear my hood. 
• Currents: We had some stronger currents this year, which is entirely possible in this part of the world. Day two and three were the days we had the most moderate current conditions. 
• Depths: Everyone was diving on nitrox, so we were able to extend our bottom times. Most of our max depths were over 20 meters, with average depths deeper than 15 meters. But there is a mix of deep and shallow sites, depending on what you like. 

Safety Protocols on the Blue Dolphin

Let’s talk about safety. When it comes to choosing a dive operator, it’s so important to pick a company that has high safety standards. 

• Dive briefings: Before every dive, we had a thorough dive briefing with our guide, Will. He walked us through the plan, reminded us of safety procedures, and told us what to look out for on each dive.
• Equipment checks: We were always reminded to check our equipment and perform our buddy checks before getting into the dinghy. They stagger the groups so that there is plenty of room on the dive deck to get ready.
• Exit and entries: You start and end every dive from the dinghy and never have to surface swim. There were no negative entries, so you always had a chance to regroup before descending on your dive.
• Emergency equipment on board: The boat is equipped with everything you could need in an emergency, though luckily, nothing was needed on our trip. The general manager, Boots, made us all feel safe with his initial boat briefing before the trip started. 
• Staff qualifications and dive guide-to-diver ratio: I have nothing but praise for all of the staff onboard. On this trip, our guide was Pitt who was incredible. With the Blue Dolphin, the maximum group size is four divers to one guide.

One thing that stands out to me about Big Blue Khao Lak is their commitment to protecting the reef. They do a check dive on every trip to make sure each of their divers has good buoyancy control and behaves appropriately in the water. 

The entire crew is outstanding and I love diving with a team that cares so much about the environment we all love so much. 

Booking and Costs

When it comes to booking your Similan Islands Liveaboard, you’ll have a lot of choices! There are a variety of boats, trips, and companies to choose from. We initially went with Big Blue Khao Lak because friends recommended them, but this year we went back because they completely blew us away. 

The Blue Dolphin MV was designed with hotel-style amenities in mind. The beds were comfortable, the food was amazing, and the atmosphere of the guests and crew was lovely. I would go back on this boat every single year. 

What’s typically included in a liveaboard?

If you’ve never booked a liveaboard, you might wonder what’s included! You can typically expect these things included in your liveaboard cost:

• Accommodation
• Meals and snacks (we had three full meals and a light snack, but there was also coffee, tea, soft drinks, fruit and biscuits available all day)
• 3-4 dives per day

You will normally pay a bit more for Nitrox, equipment, and national park fees, but with the Blue Dolphin, everything else is included. They don’t have any sneaky hidden fees. 

For up-to-date pricing and trip details, I recommend heading straight to Big Blue Khao Lak’s website. They offer price matching, which means that when you book directly with them, you’re always going to get the best price.

Final Verdict

It’s hard to believe that last year was our first ever liveaboard, because I am completely a liveaboard girl now. This trip is honestly great for anyone who wants to go diving in Thailand or who’s never done a liveaboard before. Because the trips are short, they’re great for people who aren’t sure yet whether or not they’d like liveaboards. 

The value for money on this trip is amazing. When you consider everything you’re getting (14 dives, comfortable rooms, incredible staff and tasty food), the value for money is so good.

I would book again in a heartbeat and I give this trip, crew and diving a 10/10. Don’t forget, you can mention my name (JUSTYNJEN) for free nitrox on your trip! 

What questions do you have about a Similan Islands liveaboard? Or about diving in the Similan and Surin Islands?

Planning more diving trips around Southeast Asia? Read some of my other diving guides next.

• 20 Photos to Inspire Your Trip to the Andaman Sea
• Responsible Diving in the Similan and Surin Islands
• Blue Dolphin Liveaboard Review (Similan & Surin Islands)
• Fun Diving on Koh Tao with the First Luxury Dive Catamaran
• What to Pack for a Liveaboard in Thailand

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