Koh Mook, Thailand
IN BRIEF :
Koh Mook / Muk (เกาะมุกด์) is a fairly large island just off the South West coast of Thailand. It is accessed via the mainland town of Trang and is regarded as one of the ‘Trang Islands’. Mook is not on the main farang tourist trail because there are more beautiful beaches on other, more touristic, islands nearby.
There are a few tourist resorts on Mook, mostly on Farang/Charlie Beach on the West coast. There is a large fishing community on the East side of the island.
There is water-filled cave/tunnel on the West coast which is a stop-off on most tourist boat trips. Tourists in floatation vests hold onto a rope while a tour-guide tows them through the 100m tunnel to reach an enclosed beach inside the body of the island.
Koh Mook is not known for its snorkelling, but I had seen a few maps mentioning snorkelling sites there, so I wanted to check it out. Most of the off-the-beach snorkelling is poor, but I did find some patches of gorgeous fan corals, a large patch of beautiful purple porites hard coral, a few interesting fish species and some cool looking jellyfish. Unfortunately, these were all about 2 hours swim from beach access.
It is possible to rent kayaks from a few resorts on Charlie Beach, so you could pack a mask and snorkel and go exploring by kayak. Also, during high season, you can charter longtail boats for about 1000B to go on snorkelling/cave-visit trips.
I visited in May (2012) at the end of the dry season. Weather was variable – sometimes calm and sunny, some days rainstorms and 1.5m swells. Underwater visibility wasn’t spectacular – about5- 6 metres.
There is easier snorkelling at nearby Koh Kradan and Koh Ngai.
Best-ish seascape:
Typical seascape:
All images on this site are clickable for bigger versions.
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IN NOT-SO-BRIEF:
This map is from Hat Farang Bungalows. I’m using their map because it identifies three ‘snorkelling areas’ off the West coast. I stayed at Hat Farang Bungalows – they have a wide range of decent accommodation and a great restaurant, all about 200m from Charlie Beach. Kudos to them and their map.
I have extracted the West coast and flipped it upside-down, so it looks like it would if you were stepping off Charlie Beach into the sea. That means that North is now off to the right. The letters on the map refer to the commentary below.
Note that there is an island called Koh Mak (เกาะหมาก) in the Eastern Gulf. This isn’t it.
Note that “Farang Beach/ Haat Farang” is just another name for Charlie Beach. Charlie Beach Resort occupies most of it.

Photo from Charlie Beach looking right. The headland in the right-hand foreground is Area A; the cliff further off in the distance is Area C,D and the little island in the middle is Koh Waen.
Turning Right from Charlie Beach:
The right (North) edge of Charlie Beach is all rock. It takes the form of shallow ridges
– that’s from layers of sedimentary rock which have been turned up on-end by some ancient tectonic activity, right? I’m no geologist. At low tide you will see the locals walking through the rock pools looking for some free food, trapped there when the tide went out.
Underwater in the shallows, the terrain is much the same.
As you get further out to the corner of the bay, it becomes sandy bottom 80% covered with big boulders and (mostly-dead) hump coral. It’s not too exciting here, but there are some small patches of colourful brain and finger corals; a few clams, plus the occasional large shoal of scavenging parrotfish.
As you continue heading to the right, you are into what the map calls a ‘snorkelling area’. This is really just a continuation of what we have just seen – 80% rock and brown hump-coral. The coral is in better condition round here and there are a few more fish. Among the scavengers, I saw a bannerfish and some white collared butterflyfish.
It probably looks better in the dry season when there is clear water and sunny skies, but overall, it’s not much to get excited about.
Continuing on to the right (North) there were a few jellyfish being blown in from the West.

This one is harmless. Occasionally a small reef-fish comes along and takes a chomp out of the top half. You can see the holes where this one has been breakfast.
The ‘snorkelling area’ bay is pretty big – it would take 40+ minutes of fast swimming to get from end to end. The best stuff was at the far end (Area C) , underneath the imposing cliffs. Here, I found a big (10m x 15m) patch of purple porites bracket coral at about 4 metres depth. I love this stuff.
There were also a few disc and brain corals, the occasional barrel sponge and thin layers of various corals growing on the surface of the rocks.
..but it’s quite a long way to go for something that, on average, looks like this:
This area is in the shadow of the cliffs in the late afternoon, so if you are coming, do it in the late morning.
Area C is over an hour’s swim from Charlie beach. Hardly “off the beach” snorkelling and not at all suitable for kids or noobs. A possible alternative for getting there is to hike over the hill. But be warned – it still won’t be easy-going.
There are a network of narrow tracks over the hill at the back of Sawasadee Resort and behind areas ABC. The paths are used by rubber farmers to collect the resin from the numerous rubber trees. Because there are hundreds of trees and, as you only have to visit the trees infrequently, there are dozens of tracks but none of them are very well established. You will still have to beat your way through some forest, so expect to get your legs and feet scratched up, unless you are suitably clothed. The worst patch is when you get past the end of the rubber trees and want to find your way back down to sea-level.
There are no tracks here and the going is pretty rough. If you get to the bottom, there is a deserted rocky/sandy beach here. You can safely leave your sweaty clothes on the beach while you go in for a snork, as the only people who could trouble them are kleptomaniac kayakers.
Entry into the water here is pretty difficult. You will have to step/shuffle over small rocks in the surf which are quite sharp and barnacle-encrusted. It should be fine as long as there are no waves, otherwise you will have to go very carefully and certainly have something on your feet.
There were lots of Chitons on the rocks here.
If you are heading out this way, the towering rocks are pretty impressive.
You can also see where the lapping waves have eroded the base of the cliff. Waves ride up and under these curves making an exciting crash as they head back out towards you.
There is a “Sara Cave” marked on the map. I came out here a few times (at various tidal states) and didn’t see any obvious entrance.
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Around the corner to the right is the famous Morakot (Emerald) cave. It’s about another hour’s swim through jellyfish-infested waters. So I’m not recommending you do it. Everything that follows is for kayakers.
At the point at D is a very distinctive looking angular
rock. The water is very shallow on the East side of it, so keep your distance, especially if there is any surge.
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Around the rock and heading North seemed to be a bit of a hotspot for jellyfish:
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This type was around 15cm across the bell and had tentacles about a 70cm long. I’m pretty sure it was a mean stinger, but I didn’t try it out!

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These ones were also out there and are of the stinging persuasion.

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The 30m high cliffs continue on down underwater. The bottom here is about 15 m deep. Everything is rock here – there is nothing to look at underwater.
On North for about 20 minutes, there are a couple of tall, rocky headlands, but not much else to see.

After these two headlands, you are into the long, cliff-lined bay where the Morakot (Emerald) cave is.
There is a sign at its entrance, but if you arrive in the dry season it will be identified by about 6 huge day-trip boats moored up outside and a million people in florescent lifejackets floating around the entrance, waiting to get back on their boats .
I read that there are also hawker boats that cook & sell food to the tourist boats. This leads to food scraps being thrown overboard and a population of scavenging fish hanging around here waiting for easy food.
I have been here on day-boats before, but this time I came at low season, when there was not a tourist boat in sight. Even though there was no food coming, there were big shoals of fish playing around near some rock ledges near the cave.
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It is widely accepted that you can only enter the cave at low tide. Otherwise you will kill yourself by bashing in your head on the sharp rocks in the roof of the tunnel.
Tourist boats only come here at low tide. Daytrips will shuffle their schedules around, going to other locations when it is high tide and moving their stop at Morakot for later-on, when the water has gone down and there is more headroom.
I came out here a few times in May and actually, safety has got more to do with the amount of swell (rise-and-fall of the sea water/waves) than it does the position of the tide. Tide is still a factor – you probably wouldn’t get in at the top of high-tide; but in calm seas, you wouldn’t have too much trouble getting in at low to 3/4 tides. BUT if you have half metre swells, that makes for a much scarier proposition. Even at lower tides, you don’t want to be pleading with a million tonnes of seawater that is trying to turn the top of your head into part of the ceiling decorations. Add in the pitch–darkness and to the fact that the waves and wind echo around a couple of dead-end bell chambers, singing “I’M GONNA KIIIIIILL YOOOUUU”, and you will have the (sensible) feeling to put-it-off until another day when the sea is flatter.
If you are going on a tourist boat, you won’t have to worry about any such things – they will only let you in when it is safe and you will probably wear a life-vest and go in accompanied by a guide holding a torch/flashlight.
But if you were doing it by yourself and without a torch, here’s a couple of tips:
The lowest point of the roof is at the main entrance to the cave. If you can swim under/around the chunk of rock with the white layer running through it, you should be fine for the rest of the journey.
I’m told you can do it in a kayak.
Try and go near low tide and know which way the tide is going, so you will be able to get out again later.
In the entrance hall there are some pretty stalactites, coloured by the minerals from the rocks running down them.
There is a dead-end hallway off to the right in the entrance hall. Go left for the tunnel to the beach.
The tunnel then bears round to the right, away from the sunlight in the entrance hall, so after about 30m everything goes completely pitch black. Completely pitch black. This is pretty scary if you are unaccompanied, but don’t worry as it only lasts about 20 metres. After that, the tunnel starts to curve to the left again and you get a little light from the other end of the tunnel. Not direct light from the outside, mind you. Just some dim, indirect light reflected off a distant wall. It doesn’t light the tunnel up, but it does trace out the arch of a bend at the far end, so you know where to head-for.
The tunnel is about 3 metres wide. It’s too deep to stand in the middle, but towards the edges you can touch rocks on the bottom. The roof is about 5 metres high here and the walls are pretty much vertical, so if you go slowly, you should be fine.
Here’s a ruff map of inside the tunnel. I’ve tried to shade it to indicate how light/dark each area is.

As you get close to the lit-arch, you will see a pool of ‘emerald’ water and the beach to your right. (There is also a dead-end chamber off to the left).
Have fun on the beach.
I’m sure there are a million pictures of the cave/beach on the web. Here’s one without any tourists..
Beach
If you visit near sunset, you g
et the light coming in the mouth of the cave as you swim back along the tunnel. Don’t leave it too late in the day – it will take 2 hours to swim back to Charlie beach.
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Underwater, there is not much to see (not least because it is dark!). In the entrance hall, it is mostly sandy bottom at about 2 m. Unsurprisingly, the walls of the cave continue underwater down to the ‘bottom’ at 2 metres. Outside the cave, the cliff continues down a few metres, shelves for a bit then continues down to about 10m.
I saw a picture on a blog showing a clump of bright-red soft coral on the left side of the entrance to the cave. It ain’t there no more.
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Further North from the cave, the map showed another snorkelling area at Sabaay Bay, so feeling fruity, I pressed on to have a look.
It’s another long, boring swim (almost another hour), but the cliffs above the surface are pretty impressive.
Underwater, the bottom is mostly just craggy sloping rocks down to a rocky/sandy bottom at 10m , but occasionally there is a huge chunk of rock sticking up from the bottom, providing shelter from the currents for those wanting shelter and surging upswells for those who want to feed from it.
This rock was mostly plain and boring, but it had a few spots of gorgonian fan coral and a banner fish hanging around them at 5 metres waiting for her close-up.
Approaching the corner into Sabaay Bay, I came across this big beastie swimming along. It was about 30cm across the bell and swam along with a gently pulsing motion. Purdy.
I read that this species has a strong sting. If you are wearing a mask, this isn’t a problem (they are slow moving and easy to avoid). I wouldn’t want to meet one when I couldn’t see it though.
There was a community of baby fish (not sure what they were, possibly Jacks) that hid behind this fella for
protection and/or shade. They were pretty timid – when I was closer then 2 metres they always stayed on the opposite side of the jellyfish. If I backed off, they seemed to relax and then they stayed directly underneath him, out of the hot sun.
On another trip, their Malaysian cousins decided to use me as a host!
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Sabaay bay is a big triangular affair. Roughly equilateral, with each side about 300m long. Most of the bottom is plain boring sand, about 8m deep at the mouth and sloping up gradually to flat shallows around the small beach. The snorkelling is best at the foot of the cliffs near the mouth of the bay on both sides.
On the south side at J, it is mostly rock at about 3m depth. There are some small patches of varied corals and some crazy Savadore Dali-ized barrel sponges.

Normally a barrelsponge looks like this. I assume that these ones have been messed up by the prevailing currents.

The highlight of Sabaay Bay is around point J where they are one or two rocks hosting about 10 beautifully coloured gorgonian sea fans, plus a few other interesting soft corals.
These are all concentrated in the same five square metres, so if you find it you will be happy, but if you don’t you’ll wonder what you made that three-hour swim for.
If go into the bay towards the beach, there are some interesting nooks and crannies to poke around-in on the right. The cliffs look great there, but the coral generally isn’t that special.
The water gets shallow pretty early-on as you approach the beach and there are several big rocks to stub your toe on as you walk up the sandy seabed. Up top, the setting is beautiful – a remote white sand beach surrounded by towering cliffs and raw forest with monitor lizards scurrying off into the bush and sea-eagles soaring overhead. The problem (ignoring the three hour swim) is that West-coast beaches get heaps of plastic garbage washing-up. Sabaay Bay is the perfect triangular shape to take three beachworths of crap and to squeeze it all onto one tiny beach. If you can ignore all the bottles, polystyrene foam; slippers and light-bulbs above the tide-line, then this is a lovely beach.
Actually, there is an overland track that leads to Sabaay bay/beach. But it comes all the way across from the East side of the island, starting near Koh Mook Resort. So if you were starting from Charlie Beach in the West, it would be an hour and a half walk across the island to the start of the track on the East coast and then a 2 hour walk along the track to get back to Sabaay Bay on the West coast.
I walked the first ten minutes of each end of the track, but I didn’t bother going all the way through. It was pretty overgrown in places, so you would want to wear long trousers and closed-top shoes.
Of the six maps posted around the island, only this one mentioned this track.
To find the start of the track, go to the East coast “Koh Mook Resort”; walk up through the resort, past the laundry-block and out the service entrance; then turn right along the dirt-road at the back of the resort. After about 200m there’s a signpost nailed to a tree on the left (actually the sign is facing the wrong way, so you might have to keep looking over your shoulder to notice it). The sign is written on a Koh Mook Resort’s orange sign to a “Viewpoint”. There are more signs en-route to confirm that you are still on the right track. Track/sign pics: 1 2 3 4
Swimming back out from Sabaay bay, this time on the right (North) side, the cliffs are less towering and there are more interesting chunks of rock, but there wasn’t too much different to see underwater until I neared the mouth of the bay.

Here, the main attraction was again the sea fans and mutated barrelsponges, but there were also a few fast-moving silver sea-fish like this dart, and some trevallies .
There was also this uncommon Tripletail Wrasse:
And some hazy 2 spot snappers and a deep down Blur Ringed Angelfish.
Over this side of the bay, the sea-fans are spread over a wider area and are generally in deeper water (around 4-5 metres). The barrel sponges seem even more traumatised over this side.
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I’m a swimming masochist but I wasn’t up to another 2 hours heading North to the third “snorkelling area” on the North Coast, so I decided to turn back and head back for Charlie Beach.
Swimming back across the mouth of the bay, it was a bit boring
with plain, sandy bottom at 6 – 8 metres . But one notable was this flat anemone (with resident crab and Clarkes nemo), which I haven’t seen in Thailand before.
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The return journey to Charlie beach was another two and a half hour slog over the same ground. It was interesting to see how the seascapes changed with the changing tide levels.
I saw a fun show of a jellyfish being demolished by a Java rabbitfish, but I was all out of camera battery by then.
The light was better the next day, so I did it all again!
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Turning Left out of Charlie Beach
I also checked-out the area to the left (South) of Charlie Beach. I had seen a map of dive sites that showed a divesite at a rocky islet on the South East Corner. This islet is not marked on Hat Farang Bungalow’s map.
Near the rocks on the left-side mouth of the bay, there was not much of note, but I did see a huge shoal of parrotfish.
Further round to the left (N), the water was deeper than it had been on the North (right) side. Here at Area N, it was about 7 metres deep. There was quite a lot of whip coral here and the occasional spot of vase coral.
Along the next stretch, the coral was
mostly uninspiring, but there were a few interesting beasties, like some rock lobsters and a venomous but disinterested silver-banded seasnake.
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There were also the occasional attractive coral feature.
..before time for a stop at a beautiful beach.
The little rocky island is only about 50m offshore (some maps show a larger island in the same area, but much further offshore). Access to the water over the rocks was a little difficult, but not impossible.
I had a good look around the little island. Unfortunately, the underwater visibility was terrible (around 4 metres) but it did look like it had potential for investigation on a clearer day.
The best stuff was at the side furthest from the beach and started at about 4 metres depth. I can’t tell you more than that, I’m afraid. By this stage we were at the end of May and the bad weather was settling in for the season, so visibility wasn’t going to improve any. I’m sure I’ll go back some day.
I only walked the other parts of the island. I’m guessing that the underwater terrain generally matched what was upstairs. South East had more up-ended sedimentary rocks, giving way to some sandy beaches then mud flats and mangroves as you move up the East coast. Then sand again at fancy resort Sivalai. North of the jetty was a mix of mangroves/mudflats and flat-sand beaches. The North coast looks inaccessible, according to most maps.
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Admin
There is a large muslim fishing village on the East coast, near the jetty. There are cheap eats there if you are looking for ‘local’ prices.
There are a few resorts ~400m off-left and right as you come off the jetty, but most of the tourist accommodation is 3km across the island at Haat Farang / Charlie Beach. There are about 6 resorts around Charlie Beach. Accommodation ranges from 250B shared-bathroom fan rooms, right up to fancy 3500B places with AC, swimming pools, etc.
Most resorts have restaurants and there are also a few independent restaurants around.
Dry season is ostensibly November to May, although the seasons everywhere have been getting more unpredictable lately, and this can be plus or minus six-weeks at either end.
You can get to Koh Mook from Trang town. It is a 1 hour minibus ride from the northern minibus station in Trang to Kuantungu pier (70B) then about 20 minutes by ferry boat. You can buy a minibus ticket (or a combo bus & ferry ticket) from the travel agents in Trang town for about the same price as a DIY journey.
During wet season, there is one boat per day taking supplies for the whole island. The same guy drives the minibus from Trang, then gets out and drives the boat to Mook. In dry season, there is a wider and more frequent range of buses and ferries.
The Emerald cave on Koh Mook is a stop-off on “4-island” snorkelling day-trips from Koh Lanta and Pak Meng. Daytrips from Koh Lanta are about 1000B, from Pak Meng/Trang, about 800B. These boats don’t actually land on Koh Mook, but you could (have a resort) arrange for a long-tail boat to transfer you off the big-boat and take you to Mook.
Here is a list of longtail boat prices for trips and transport from Koh Mook (@2012).
The venerable Tezza gives lots of information about the island here.
Linkies:
Alternative maps:
1 – Yellow one
2 – Paper one
3 – Police station one
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Visited: May 2012 Last updated: May 2012


















































































































Thanks for your painstaking research. I’ve always regarded Muk as a dud snorkelling-wise – but you have shown that a true enthusiast can find something.