A Brief Overview of Liveaboard Scuba Diving in the Similan Islands


The Similan islands are an archipelago off the south western coast of Thailand, about 120km north west of Phuket island in the Andaman sea. Liveaboard scuba diving in the Similan islands is hands down one of the best things I have done!

This is perhaps due to the amazing dive that I was lucky enough to have with a whale shark circling and feeding for 45 minutes on the very last day of my trip. I decided to go liveaboard scuba diving in the Similan islands after much research and evaluating the cost to value ratio for my needs and figured it was the ideal way to scuba dive in the area.

The Similand islands consist of 11 islands, including national park regions which incur a fee upon entering. The islands sometimes close for years to assist with rehabilitation. The envorionmental impact it had on the area was just too much. Much of the accommodation has been removed, save for a handful of bungalows on the largest island.

These days the numbes of visitors per day is capped at 3,850 per day and overnight accommodation has been torn down. This is great news for those wanting to go liveaboard scuba diving in the Similan islands, which let’s be honest is the absolute best way to see the area!

Scuba diving in the Similan islands is still big business, with hundreds of thousands of visitors per year. Although you can dive from the mainland on day trips, I highly recommend you use liveaboard scuba diving to your advantage when diving in the Similan islands (budget and time permitting).

In this post I will explain why liveaboard scuba diving in the Similan islands is worth considering, as well as why it might not be your cup of tea. I will also give a brief overview of the MV Oktavia 6 nights / 5 day liveaboard tour of the Similan islands.


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(Shot using the Sony a7R III with the Sony FE 16-35mm f/4).

4 Reasons to go Liveaboard Scuba Diving in the Similan Islands 


There are any number of reasons that you should go liveaboard scuba diving in the Similan islands, but without wanting to waffle on too much I shall keep it to 4 of the main reasons.


Composition of the Dive Sites

The rocky composition of the ocean floor makes for stunning underwater scenery, before even taking into account the variety of marine life that calls the area home.

Some dive sites involve pinnacles, some have large sloping granite walls, others boulders. There will be the opportunity to swim through caves, in between large granite walls and through underwater canyons.

The underwater seascape and topography is some of the best in the world.



The area will consistently give you visibility upwards of 20 metres. It is more likely to be around the 30 metre mark however, with crystal clear water providing better diving conditions and a more enjoyable dive.

My tour was plagued by “poor visibility”, but this is all relative to the area. The visibility was still 20 metres, and the reason it was lower than normal was due to increased plankton. This led to us seeing whale sharks and manta rays though, which come to feed.

So I would take that over an extra 10 metres visibility any day of the week!


Marine Life

As mentioned already, there is the chance here to se whale sharks and manta rays, which are the stars of the show. But there are many other things to see, as is true with anywhere that provides good feeding grounds. Other things I saw during my visit include;

  • Black tip sharks.
  • Octopus.
  • Moray eels.
  • Seahorse.
  • Barracuda.
  • Giant Travelly.
  • Tuna.
  • Sea snakes.
  • Stingrays.
  • …and plenty more!

The dive sites were always full of so much marine life that the post dive debriefs were often so hard to try recall every little thing that you saw during the dive.



Liveaboard scuba diving in the Similan islands doesn’t involve veering far from the path of the general backpacking trip through Thailand anyway. They are not located in such a difficult part of the world that requires you to go out of your way to get there.

Not only that, but their accessibility and relative proximity to shore helps keep the costs down, relative to other liveaboard trips around the world, that need to venture to more remote parts of the world.

There is also the possibility of doing a shorter liveaboard scuba dive trip than the 6 nights that I did.  Shorter trips are on offer, as well as day trips from the mainland.

3 Reasons You May Not Want to Try Liveaboard Scuba Diving in the Similan Islands


This is a bit of a stretch to try come up with 3 reasons that you might not be interested in a scuba diving trip. Assuming that you like scuba diving of course, which would make sense if you’re reading this post. But I’ll try my best to think of 3 reasons.



Despite the relatively low costs for liveaboard scuba diving in the Similan islands, the tours are by no means cheap! For those touring Southeast Asia on a budget, then this is probably not going to be something you can justify to yourself.

I will cover costs in more detail further down this post, but for quick reference, the tour I did cost me $1,388 AUD. This was before gear rental, national park fees and tips.



This goes against the grain of what I said about accessibility previously but let me explain. Although a lot of backpackers will travel through the south of Thailand, many will see the islands on the east coast such as Koh Samui and Koh Phanang which sit in the gulf of Thailand, not in the Andaman sea.

The island of Phuket can be avoided and the towns that are closest to the dive sites on the mainland such as Khao Lak are trash. I found them overpriced and just a mish-mash of westernised crap. I would avoid them completely unless specifically staying overnight before a dive trip.

An exception to this is those who go to Khao Sok national park, which is a great place to see with great activities and will lead you in the general direction of the Similan islands.

In summary, the mainland cities and towns are some of the less inspiring ones you will see so you may be skipping the region altogether, which is fine.


Diving Competency

These islands are not overly difficult dives, but they can be!

Some conditions are absolutely fine for beginners, others involve strong currents and sharp reef or boulders that could injure you without good bouyancy control. I think it will be ok for most people, but if you’re not confident then it would be a shame to book such a long tour and then never enjoy yourself during the dive.

Some boat operators will ask for a minimum number of dives, usually around the 20 dive mark. They can offer refresher courses for those who haven’t gone scuba diving in a long time, you will have to contact the tour operator for more information about that on a case by case basis.

When to go Scuba Diving in the Similan Islands?


The Similan islands are closed during the wet season to tourists to help the area rehabilitate and to slow the degradation of the environment. The islands are open from November to May.

The best time to see the whale sharks is normally between February and April, but sightings are possible in earlier months as well.

Scuba Life

(Shot using the Sony a7R III with the Sony FE 16-35mm f/4).

MV Oktavia – 6 nights / 5 days Tour


I decided to book my liveaboard scuba diving trip with MV Oktavia after reading some limited reviews, it was  hard to get good information but the boat seemed like it was a good middle ground with good food and a great crew.

The crew were indeed great, and I have no regrets about booking with MV Oktavia, so let’s discuss the tour a little bit and get some quick information out.


MV Oktavia Overview

The MV Oktavia is one of many options for a liveaboard scuba diving trip in the Similan islands. It is a middle class option, not being the fanciest option but also being a few hundred more than the cheapest tours – Manta Queen 7 (generally the cheapest).

The boat is 30m long, 6.5 metres wide and although it can sleep about 30 people, the numbers are generally limited to 20 for comfort.

There are a variety of rooms available depending on budget and travelling arrangements, I personally had a twin cabin, but I had the room to myself due to COVID-19 and the high Thai Baht making the tourism weaker in early 2020.


What are the rooms like onboard the MV Oktavia?

The rooms onboard are comfortable for people of most heights. I am 6 foot and fit comfortably. The rooms have air-conditioning and power-points to charge all of your electronics.

The more expensive rooms will have ensuite bathrooms but otherwise there are shared toilets and showers. They were always kept clean and the only time there is a queue is straight after a night dive, but the wait is never too long.

The beds themselves are comfortable and warm and the storage option plenty. In saying that though I was lucky enough to get a room to myself.


How much does the MV Oktavia cost?

I have decided to provide the costs in the local currency, as this is what you will pay your tips, gear rental, and national park fees in. However your tour will often be booked in your own currency if you’re booking in advance from home.

Keeping in mind that all prices are subject to change, but here are my costs that I paid in early 2020;

($1,375 AUD, $1,045 US, £770, €860)

($310 AUD, $235 US, £175, €195)

($90 AUD, $65 US, £50, €55)

*This is up to personal preference and your own financial situation of course and is only a guide.

Where does the MV Oktavia depart from and return to?

The MV Oktavia leaves from a place called Thap Lamu Pier, which is about 11km south of the main centre of Khao Lak. This is also where you will be dropped off on the last day of the trip at about 18:00 in the evening, with shuttles ready to take you to your final destination that evening.

How do you get here?

There are services at extra cost to be picked up from places as far as Phuket island. I was picked up at the south of Phuket and it cost ฿1,500. The drive was around 2 and a half hours.

This cost is shared if there is more than one person coming from the same location however, I was not so lucky.

Alternatively you can find your own way to the area, or spend the night in Khao Lak. There are public bus routes that run from the south of Thailand towards Khao Sok national park, they run straight through Khao Lak and are easy to catch, as well as dirt cheap.

However they are sometimes difficult if you have a lot of luggage as space can be limited.



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Big Girl

(Shot using the GoPro Hero 7 Black with the Dive Housing).

The Scuba Diving


The main reason people come here, the diving!

There are a lot of dive sites in the area, each island is normally home to multiple places that can be visited, this post won’t cover them all but will give a brief overview of some of the more popular and more renowned dive sites.


How many dives do you do on a liveaboard diving tour in the Similan islands?

Every boat is different, but for this area the most common lengths of tours are 4-5 days and will involve 4 dives per day.

The MV Oktavia 5 day tour involved 19 dives. This was more than enough to satisfy anyone, with surface breaks just long enough to let your body reset and allow you to dive for optimal times each go.

The first 3 days involve a night time dive in protected bays by torchlight. The 4th day involved and evening dive to see the schooling and feeding fish, these are often the best dives to witness.

What dive sites does the MV Oktavia dive at?

Although this is listed on their website, it is also subject to slight changes.

The changes may be for safety reasons, due to current strength and direction, or for your own enjoyment. For example, our last day of diving we did not dive at the Bonsoon wreck on the way back, but instead we dove at Koh Tachai twice and then Koh Bon.

The reason for this was because there were feeding manta rays, and all of the captains communicate this with each other. Not only that, but due to the plankton count, we were lucky enough to have a whale shark grace us with its presence for 45 minutes at Koh Bon.

Every other dive boat had already deployed their divers, so were left in the water alone with the whale shark as it was feeding, and all the other divers resurfaced. it was awesome.

What are the best dive sites visited?

This is of course subjective and depends largely on what you see, as well as what you hope to see. However there are a number of the sites that stand out more than others, I won’t go through every site, but some of the better ones are;


Richelieu rock

Richelieu rock is the one that everyone wants to come and see. The rock is visible from the surface at low tide only, then disappears beneath the surface as the tide goes up. The rock is a horse shoe shape, with most of the dive being about 20 metres in depth.

The currents can be very strong here and dive times can be cut short if you exert yourself, but there is normally one side of the rock that is protected. The marine life here is the big selling point.

schools of predatory fish gather at sunrise and sunset for feeding, massive schools of barracuda and giant travelly were there when I was there. This location is also good for whale sharks and manta rays.

Although we did see whale sharks here, the currents were too strong to be enjoyable and they disappeared into the blue. There are many other things to see, including sea horses.


Koh Tachai

Koh Tachai is probably the second most renowned dive site on the tour behind Richelieu rock. These two locations are the best spots to see schools of feeding fish, which is a sight to behold!

On top of this we also had a brief glimpse of a whale shark out in the blue. The currents can be strong depending on where you dive, but it creates great feeding grounds for the schools of larger fish.


Koh Bon

My favourite of all the dive sites, but purely due to my elongated whale shark and manta ray interaction.

The dive normally happens either side of a wall/ridge on the western edge of the island. It is a great place to see manta ray, but there are other thins that will keep you occupied in the mean time.

It is also a good place to see some shark species, moray eels, and of course if you’re lucky, whale sharks.


Elephant Head Rock

Elephant head rock was one of my favourite dive sites, not for the marine life, but for the topography of the boulders under the water. There is plenty of caves, canyons, swim-throughs, and just amazing scenery all around you!

That’s not to diminish the wildlife here, which is as plentiful as all the other dive sites (save for Richelieu rock and Koh Tachai perhaps).

Don’t take things for granite!

Liveaboard Scuba Diving Video


See a video showing some of the excitement of liveaboard scuba diving in the Similan islands aboard the MV Oktavia. It will give you a greater understanding of the room sizes, boat layout, and just how close we got to whale sharks.

Some of the underwater footage isn’t the best, being from a GoPro with a red filter and some pretty questionable white balance, but you get the idea regardless.

Bright young women, sick of swimmin’ …. ready to stand!

(Photo courtesy of @youngsam.j).

The Day Trips


It isn;t just the scuba diving that might interest you, although it is the only reason you will book these tours, there are day trips to the islands included to break things up and keep things fresh.

The islands can’t all be visited, but there will be 2 or 3 beach trips to give you a chance to go for a swim or relax on the sand. The scenery on the largest island is incredible. That is island 9, or Koh Similan as it’s sometimes called.

This particular island is often photographed thanks to the large boulder that sits precariously atop the boulders and granite below. You can walk up to the top of this mound and enjoy the view of the bays below.

The bay has crystal clear waters and is well protected. The climb up to the lookout point is very easy and anyone with the slightest mobility should be able to do it with ease.

The two pictures below shoe just some of the views you will see, first from the beaach looking up towards the lookout, and secondly from the lookout, but looking back towards the back of the island, not towards the bay where the boats are moored.

(Shot using the Sony a7R III with the Sony FE 70-300mm f/4.5-5.6).


(Shot using the Sony a7R III with the Sony FE 16-35mm f/4).

Things to Consider


Don’t book this trip feeling like you are guaranteed to see a whale shark, or even a manta ray. The chances are higher than in other areas, but these things are never promised.

However if you want to see large schools of predatory fish, large variety of marine life big and small, and want to dive 4 times a day, then this could be right up your alley.

It provides you with a condensed amount of diving that will improve your skills as you go. On top of this is the chance to see amazingly large and graceful whawle sharks, but don’t be put off if it doesn’t happen for you.

Good luck!

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