Similan Scuba Diving Dive Sites: Koh Tachai

Koh Tachai

The Main site is located just off the Southern tip of Koh Tachai. located withing the boundaries of the Similan Islands National Park, but geologically separate.

As there are can be cold currents from the ocean tides that are quite strong here -  divers are recommended to wear a proper wetsuit when diving in this spot.

This site features rock corals and sea fans with plenty of huge marine life cruising around.

Diving here requires the use of the guide rope connected to the buoys (there are two), as a strong current might sweep divers out of the intended target. This also means making sure you only dive with boats and staff that are safe and aware of diving conditions – please avoid untrained and inexperienced liveaboards.

Leopard Sharks, Manta Rays and even Whale Sharks are among the visitors to this site.

Always choose a dive center that has staff speaking your language, have insurance and are certified.

Similan Scuba Diving

With some fish, critters and coral out there – it is hard to sometimes realize that the stories and details about each species can be truly amazing. There are several stories and lots of information about the Marine life around the Similan Islands. I had a good laugh about some of the analogies made!

There are some articles about Bumphead parrotfish, nudibranchs and turtles. These are all things tat people commonly see and are curious to learn more about.

However the articles on the Wenteltraps and Cuttlefish were really fun to read. Not just scientific dribble that you see in a lot of these postings.

from the cuttlefish article:
“Space ships. I don’t think I have ever dived anywhere else where I have seen so many space ships (cuttlefish – and not just during night dives but during the day as well. For me these highly evolved, highly intelligent, elephantine mollusks have always appeared extraterrestrial. The way in which they hover, speed backwards and perform a stunning display of electric flashes so utterly hypnotic that leaves you wondering what level of evolution they have achieved.”

The best time to visit the Similan Islands National Marine Park is from mid October to early May. It is during this time that the seas are calm, the visibility is at its very best, and the large Marine Life (like Whale Sharks and Manta Rays) are making their annual migrations to feed on yearly plankton blooms. The water temperature around the Similans varies between 27 and 29 degrees Celsius, so most divers prefer a 3 mm wetsuit. Depending on environmental factors the water clarity ranges from 10 to 40 meters. Adventures to the nine islands of this amazing archipelago can either be done by Similan Liveaboard or day trip diving from Khao Lak. The Similan Islands National Park closes from May to October when western Thailand is experiencing the southeastern monsoons.

-Similan Diving

What is the visibility like on the Similan Islands?

The Visibility at the Similan Islands

The Similan Islands are known for the great diving, incredible marine life and…of course….the visibility. Throughout the year we experience 20 meters (70 feet) visibility on average. During the very flat seas on February and March we can have further.

As the Similan Islands are quite close to the Continental shelf we can get some amazing cold water upwellings. These bring Plankton blooms and colder water. However, this is part of what makes the islands so vibrant! This feeds much fo th marine life – from the corals themselves to the Whale Sharks and Manta Rays!

During the upwellings, visibility can drop to 1015 meters (30-50 feet), but there is still so much to experience! The corals are still there, as are the fish and…do we need to mention…the beaches!

One final word – The Similan Islands visibility is never afected by the mainland! The runoff and pollution is too far away to affect the visibility. So diving is great all the year-round – it’s only the safety of getting there that allows us to vist only 7 months of the year.

-Khao Lak Diving

Similan Diving April 16, 2008

Today there was some seriously great weather. On the mainland we could see the rain and storms building up, but it never affected us on the way out.

With a diverse group – Advanced divers, an Open water course and a DSD we had a bit of everything.

Marcel took the DSD and made his student happy. Tuk, great as always with his Open Water students.

Filip also took a group to Bon Soong today and it was good. Viz at 15 meters+ and that was very nice.

Khao Lak Diving