Green Rock dive site, Koh Tao

Marine life around Green Rock, Koh Tao

Diving Koh Tao – Green Rock

It will soon be a year since I became a PADI Diving Instructor here on Koh Tao and over two years that I have been living and diving on this beautiful rock, our Turtle Island. Recently one of my students asked me what my favorite dive site was.

Good question! I hadn’t really thought about this for quite a while.

Green Rock Dive Site Has Unique Characteristics

Of course, you have the famous Sail RockChumphon PinnacleSouth-West Pinnacles and Shark Island that are all, on their day, spectacular Koh Tao dive sites. They are deeper dive sites offering a wide variety of marine life and of course, for our lucky divers, Whalesharks are often spotted here.

However, for me, Green Rock is a little bit different to the rest and I have had some awesome dives there. Here is why this cluster of large underwater boulders and rocks is my favourite Koh Tao dive site.

Hin Keow (Green Rock)

Green Rock really is a ‘fun’ spot to dive. Ideal for all level of divers, offering a depth of up to 28 meters from 4 meters on the top of the Rock. From the Open Water diver to the most experienced Divemaster, Green Rock will please every level of divers.

Located just to the North West of Koh Nangyuan Island, it offers a diver so much to explore, so much to discover if you pay attention and know where to look.

During a dive around Hin Keow (‘Rock Green’ in Thai) you have the possibility to enjoy the spectacular Rock’s formations, hiding an abundance of secrets or you can swim along the coastline of Koh Nang Yuan Island, which offers a different landscape to the main site, including a wider variety of corals.

It’s a Rocky Dive

The main pinnacle of the dive site almost breaks the surface and you can see it before your dive from the boat. The rock formation then drops down to depths around 28 meters. The many boulders make the site a great place to explore its many ‘nooks and crannies’, spotting some cool marine life hiding away along the way.

The rocks also create some great swim-throughs. These are great tests for your buoyancy and give you an exciting experience as you pass through the rocks, exiting on the opposite side of the dive site. After over 10 years of scuba diving, every swim thru is a new exploration that I still enjoy.

However, you need to be careful because those lovely swim-throughs sometimes can turn into the playground for Koh Tao’s famous Triggerfish.

This is probably a good time to talk about another attraction of this great dive site.

Trigger Fish Facts

The ‘Trigger Pit’ is an area of sand, located north of the main dive site, that both Yellow margin and Titan triggerfish have made their home. The ‘Trigger Pit’ is a particularly busy part of the dive site during the mating season when females will nest whilst the males will aggressively keep guard.

What was once a sandy patch has been transformed into a ‘Moon’ like landscape, with scattering of rocks and corals. The Triggerfish are clearly the resident owners of this patch of underwater real estate and the only ones allowed to enter this unusual area of the dive site – unless you are a very brave scuba diver!

An Important Reminder

It doesn’t matter how colourful and interesting these Triggerfish look, nor ho docile they can be when outside of their nesting area, they are incredibly territorial and don’t like trespassers. I recommend keeping your distance, watching from afar.

Many divers have funny stories of getting ‘triggered’, although it’s anything but funny at the time. That I can testify to! However, if you keep your distance, swim around their nest and adhere to normal respected underwater practices, then you can enjoy these amazing creatures in all their glory.

The Marine Life

You will see most of the marine life found at most of Koh Tao’s dive sites. However, this is one of the better spots to see, on occasion, both green and hawksbill turtles. There are many groupers and blue-spot fantailed rays, often found in the caves and under many kedges, as well as many of the micro marine life that I love such as nudibranch or saw blade shrimps.

My Favourite Dive Site on Koh Tao

I am lucky enough to dive Green Rock regularly but often I am teaching so naturally my focus is on my student divers than on all the wonderful marine life you can spot, and fun you can have around the dive site. 
Recently I found the time to go fun diving with two of my friends, both videographers who also really enjoy diving Green Rock and we had an amazing dive!

I am completely in love with Yellow boxfish that are without doubt my favourite fish – they are just so cute! I was swimming, exploring and looking in all the holes, nooks and crannys hoping to see something unusual things, when not very deep in a small crack I discovered this adorable baby round yellow box fish. Such a cutie, and even more cute, the little guy was swimming upside down.

As it was inside this small crack it was finding it difficult to orientate itself as it could tell the difference between the bottom and the top. Hilarious! I always keep an eye out for my little boxfish when visiting Green Rock and have seen him grow up but he has now moved on, away from that little crack where I viewed one of his offspring and into the big wide sea.

Also on this dive I was able to see a Scorpion fish one of only 2 places I have seen them around Koh Tao. You need good eyes to spot them and you always get a great sense of achievement after spotting one.

My Favourite Place

Green rock offers so many different things and it grows on you as you become familiar with the dive site. This is the perfect place to take pictures, see great marine life and explore between the underwater boulders. Make sure you take a torch with you the colors inside the swim through will look even more amazing.

I highly recommend adding Green Rock dive site to your Koh Tao diving list!

A PADI Instructor and colleague at Crystal Dive took both the Scorpion Fish and Yellow Boxfish photos on this dive.

Author: Marie Suzanne-Houbiers (PADI MSDT #370229)

Crystal Dive Koh Tao

7/1 Moo 2
Tambon Ko Tao
Koh Tao
Surat Thani

E-mail: [email protected]

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