Richelieu Rock
The beautiful Andaman Sea that surrounds the Similan and Surin Islands is a world-class diving desti
Explore Similan Islands
Nestled in the heart of the Andaman Sea, the Similan Islands are a true diver's paradise, offering an enchanting underwater experience that is unparalleled. These nine islands, part of the Mu Koh Similan National Park, boast some of the most vibrant marine life in Thailand. Divers can expect to be mesmerized by an array of colorful tropical species, along with the thrill of encountering majestic manta rays and elusive whale sharks. The islands are mostly uninhabited and protected, providing a sanctuary for nesting turtles, adding to the region's natural allure.
Exploration here is best done via liveaboard, offering divers of all skill levels access to the range of underwater splendors. From dramatic sloping reefs on the eastern side to awe-inspiring rocky boulder formations in the west, the underwater topography is diverse and captivating. Dive sites feature tunnels, caves, and swim-throughs created by submerged granite boulders. Whether you're just starting or are an experienced diver, the clear waters and excellent conditions make the Similan Islands an unmissable destination.
While day trips from Phuket or Khao Lak are simple and convenient, dedicating a few days on a liveaboard offers a deeper connection to the region's pristine environment. The best time to visit is between February and April when conditions are ideal, ensuring you experience the islands at their finest. This remarkable destination, with its unparalleled diving opportunities, truly stands out as a treasure of the Andaman Sea, beckoning divers from all over the world.
Top Regions to Explore
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Dive Activity
Diving in Similan Islands
As a whole, expect an array of colorful reef diving spots all over the islands. Of the 25 or so dive sites in the Similan Islands, most feature fantastic hard and soft coral reefs overflowing with life, which explains is popularity. Many sites also feature impressive underwater structures, such as swim-throughs, tunnels and caves, making cave diving another possibility for qualified thrill-seekers.
Wall diving is also just as epic due to intensely dramatic underwater seascapes, in addition to some exceptional deep diving sites that are more suited to experienced divers. Plenty of encrusted pinnacles are peppered around the entirety of this underwater wonderland, and with many of such sites exposed to the open ocean, they can experience currents, making for some exhilarating drift dives.
Though it’s not super-popular here, wreck diving is possible in the area, with the most famous being the Tuna Wreck, which was sunk in 2003 to serve as an artificial reef structure.
Top Wildlife Sightings in Similan Islands
It’d be more accurate to ask what marine life can’t be seen when scuba diving in the Similan Islands. A plethora of hard and soft coral species, gorgonian sea fans and colorful sponges all decorate reefs, rocks and pinnacles that compliment the dive sites here.
Schooling fish, like tornadoes of barracuda, snapper and hunting trevally are common sights, as are colorful reef fish like anemonefish, triggerfish, lionfish, angelfish, bannerfish, batfish, damsels and so many more. Masters of camouflage like scorpionfish, frogfish, stonefish, cuttlefish and octopus blend in and pleasantly surprise divers, while macro delights like nudibranch and shrimp pose for photographs.
Reef sharks like black tips and leopard sharks can be spotted, and other curious critters to encounter include moray eels, crabs, lobster, seahorses, stingrays and pipefish. The big boys also visit the islands, especially from February to May, so if manta rays and whalesharks excite you, add the Similans to your must-dive list.
Wildlife Sightings are Based on User Generated Content
The image shown is a representative illustration and does not depict every individual animal in this category.
Total number of species approx.: 200
Alamy-WaterFrame
Moray Eel
3.2k Sightings
J
462
F
520
M
546
A
454
M
83
J
12
J
13
A
27
S
11
O
144
N
427
D
499
Shutterstock-Shane Myers Photography
Green Turtle
1.2k Sightings
J
183
F
186
M
216
A
148
M
34
J
7
J
8
A
20
S
9
O
35
N
125
D
231
The image shown is a representative illustration and does not depict every individual animal in this category.
Total number of species approx.: 27
iStock-Global_Pics
Barracuda
920 Sightings
J
99
F
166
M
236
A
125
M
25
J
2
J
4
A
24
S
3
O
58
N
65
D
113
The image shown is a representative illustration and does not depict every individual animal in this category.
Total number of species approx.: 300
Alamy/Reinhard Dirscherl
Octopus
482 Sightings
J
69
F
56
M
154
A
72
M
25
J
2
J
5
A
2
S
1
O
4
N
40
D
52
The image shown is a representative illustration and does not depict every individual animal in this category.
Total number of species approx.: 600
iStock/ultramarinfoto
Wrasse
434 Sightings
J
56
F
97
M
120
A
82
M
4
J
5
J
0
A
4
S
0
O
7
N
38
D
21
Shutterstock-Andrey Armyagov
Hawksbill Turtle
407 Sightings
J
60
F
79
M
81
A
65
M
6
J
2
J
0
A
8
S
0
O
16
N
34
D
56
The image shown is a representative illustration and does not depict every individual animal in this category.
Total number of species approx.: 28
Udo Kefrig
Clownfish
3k Sightings
J
428
F
487
M
604
A
410
M
62
J
24
J
44
A
67
S
48
O
128
N
324
D
422
The image shown is a representative illustration and does not depict every individual animal in this category.
Total number of species approx.: 100
iStock-burnsboxco
Parrotfish
2.8k Sightings
J
417
F
462
M
543
A
388
M
47
J
16
J
22
A
43
S
33
O
116
N
335
D
418
The image shown is a representative illustration and does not depict every individual animal in this category.
Total number of species approx.: 90
Shutterstock-Rich Carey
Angelfish
2.4k Sightings
J
343
F
395
M
410
A
314
M
43
J
18
J
34
A
55
S
32
O
101
N
262
D
380
The image shown is a representative illustration and does not depict every individual animal in this category.
Total number of species approx.: 40
iStock-wrangel
Triggerfish
2.3k Sightings
J
329
F
371
M
417
A
306
M
44
J
10
J
21
A
31
S
19
O
90
N
288
D
347
The best Months to dive in Similan Islands
Scuba diving is possible year-round in the region, as the area benefits from a warm tropical climate. November to May is the main liveaboard season, while day and overnight trips run from October to May.
The best season to dive is normally between February and April, when calm seas are the norm, and visibility is at its clearest, ranging between 25-40 meters. Rainfall is also rare in these months, and sunny, clear skies are pretty much guaranteed daily. Air and water temperatures fluctuate between 26°C-30°C (79°F-86°F) all year, with the latter peaking between February and May.
As currents increase around the end of February, pelagics like mantas and whalesharks are attracted to the dive sites, so be sure to visit during this time to have a higher chance of bumping into them.
Be aware that the Similan Islands are open for diving from October 15th until May 15th annually, so be sure to book your trip within this time frame, as they’re closed for the rest of the year.
