Gulf of Thailand, April 2006

Imagine a deep blue sea and a clear blue sky, all around you, as far as the eye can see...


Standing on the M/V Trident's upper deck, that's exactly the view I enjoy right now. Slowly sipping my early morning coffee. Waiting for the sun to rise just a little bit more, so as to have more light penetrating the water.

Everything's ready, I just need to gear up and splash in for some deep wreck diving!

trip report
travel blog

Thailand - info sheet

Visum	Belgian citizens automatically get a four weeks visum upon entry. For longer stays a visum must be requested beforehand. In Copenhagen, a two months visum can be obtained from the Thai embassy within a week. Besides your passport you must bring two pictures, a copy of your Danish residence permit & travel documents, fill in an application, and pay 175 DKK.
Time	Bangkok time = Copenhagen summer time + 5h
Weather	Air temperature's around 35°C, very humid with occasional tropical showers. Water temperature's a balmy 29°C.
Currency	1 Euro = 46 THB 1 USD = 37 THB
Language	English is barely spoken by some.

Deep wreck diving in Thailand?

Two and a half years ago I got trimix certified and followed an advanced wreck diving course in the Philippines. So it was about time to put the two together. But where? Having been invited on an exploratory deep wreck diving expedition in Sri Lanka, I needed a place relatively nearby where I could refresh my skills, in preferably similar conditions. Subic bay in the Philippines not being my favourite place, I checked out my options in Thailand.

Even though Thailand doesn't immediately pop up as a possible destination when thinking about technical diving. There's some deep diving going on on its west coast, with Mark Ellyatt having put Phuket on the tec diving map thanks to his 313m deep record dive, but there are -as yet- no wrecks to speak of. And on the east side, the Gulf of Thailand is a rather unknown place when it comes to wreck diving. That is, until you start looking a bit deeper.


Somehow, a Google search resulted in a link to the M/V Trident. And it immediately caught my interest, offering exactly what I was looking for: exploratory deep wreck diving! Co-owned by Jamie McLeod (tec instructor trainer) and Stewart Oehl (tec instructor), two British expats living on Koh Tao, the M/V Trident is currently the only ship organizing deep wreck diving expeditions in the Gulf of Thailand. Besides the owners, there's also Michael (tec diver), another British expat, who acts as divemaster & gas blender, and of course there's the ship's Thai crew: captain, cook, engineer & deckhand.


In less than a year Jamie & Stewart have found over a dozen wrecks, lying in 50-70m deep water. From wooden fishing boats to cargo vessels to WWII war ships. And they've got plenty more marks and sonar glitches to check out. One wreck in particular has gotten them a lot of media attention, both good and bad: the USS Lagarto, a WWII United States submarine sunk by the Japanese in May 1945 and now lying 70m below the waves. Considered a war grave, it's alas a no go site.

Thanks to the M/V Trident, the Gulf of Thailand is indeed becoming a serious wreck diving area, with virgin undived wrecks waiting to be found.

The Tattoo bar

When not looking for wrecks, the M/V Trident's dive crew can often be found in the Tattoo bar, a beach-side British hang-out, only a short stroll from Master divers in Mae Haad bay. Cold beers, English pies, American burgers, New Zealand steaks, beautiful Thai sunsets, ... What else could you wish for when stuck on dry land?

This is where I first met Jamie & co after arriving on Koh Tao a couple of days ago and it's here we all gathered yesterday evening before sailing out into the Gulf. Stewart rejoicing over the fact that, yes, I do occasionally have a beer too.

Boarding & departure

I'd actually already boarded earlier in the day, as I'd had to vacate my bungalow, check-out time being 11am. A group having cancelled last minute, it turns out there's only one other diver besides me. Meaning I've got a three bunk cabin all for myself. And being the first one on board I even got to pick which one. What a luxury!


My few non-diving-gear belongings quickly thrown in one of the lower deck cabins, the first thing I did was to take advantage of the bright daylight to check and set up my gear. After which I just made myself at home and relaxed.

A little after 8pm we took off, with an offering of noisy fire crackers to appease the gods, before heading out to sea. Once we'd left Koh Tao behind, it went all black around us.


Sitting on the upper deck, Jamie tells me about the HTMS Pangan, the wreck we'll be diving the next few days. Weather & time permitting, we might also check out an unknown mark. The last two days are reserved for Big Boy, an as yet unidentified wreck, which they've only dived once before in rather rough conditions. In other words: adventure guaranteed! Briefing done, Stewart shows me how to use his dive planning software. Just so as to keep my feet on the deck.

The HTMS Pangan's history

The HTMS Pangan was a Royal Thai Navy Transport, built in Japan in 1927, about 60m long & 10m wide, 1874 tons empty & 2442 tons full, with 2 diesel engines and 3 guns (60, 40 & 20mm).

She sank the 19th of July 1961, at 10pm, off the coast of Surathani. Her entire crew (81 souls) was saved six hours later by a Japanese freighter. Why she sank however is not too clear. She'd left Bangkok earlier that week carrying 'damaged' ammunition & gunpowder to be dumped at sea.

Officially she went out of control and the crew abandoned ship when her main engine broke down after battling heavy seas for several hours. Supposedly a large wave had hit the ship, some of the cargo broke loose and rolled to one side, making her list heavily and take more waves. Totally swamped the pumps & engines failed. Rough seas would have been very unusual at that time of the year and the cargo might not have been as properly strapped down as it should have. More probable however, from the damage on the wreck, a fire broke out and she went down ablaze...

Deep wreck diving stop by stop

How to find a wreck

Basically, it takes a lot of dedicated research to find a wreck. Knowing what you're looking for is probably a good start. Knowing where to look is next. Or vice-versa. There're bound to be some kind of records somewhere, be it maritime archives or battle reports. Anything that might give you an approximate location will do. After that it's search & explore.

Wrecks attract fish. So having your ears tuned into the fishermen's grapevine might give you some good clues as to where to look. Though they're most likely to be very protective of their best fishing locations.

And while you're out there anyways, why not keep your sonar on. Who knows, you might just get lucky and stumble upon something.

One way or another, Jamie & Stewart have already found several wrecks over the past year and still have a whole bunch of probable & unknown marks and mysterious sonar glitches to investigate. All written down in Jamie's little book of secret coordinates.

Getting there

We sailed all night, arriving in the early morning, seemingly in the middle of nowhere. It's actually the sudden quietness that woke me up, after having been lulled to sleep by the constant throbbing of the engines.

Using GPS coordinates the captain steered the M/V Trident to the wreck's approximate position. After which a search pattern was performed using the sonar to pinpoint it as accurately as possible. On his signal a deckhand then let go of a drop line, a relatively thin line weighted down by about 10kg of lead at one end and kept afloat by a buoy at its top end.

Anchoring

No anchor was actually dropped. In stead, Stewart jumped in the water, fully geared up for action, to go and tie down the M/V Trident directly to the wreck.

Depending on the conditions, one or two crew divers jump in the water near the drop line's buoy and are handed the end of a ticker line, after which they descend into the blue looking for the wreck.


If they're lucky they'll be able to see it on their way down, or find it thanks to the fish that usually hang around a wreck's vicinity, using it as shelter. If the visibility is bad they might need to perform a circular search using a reel attached to the drop line. If unlucky they may have to resurface and the whole procedure then needs to be repeated from scratch for another try.

Usually though, as was the case this morning, they find the wreck on the first try, tie off the line, give three strong thugs to signal the surface crew of the successful tie off and either resurface immediately or after performing a short dive. At this point the M/V Trident is securely tied to the wreck, thus ensuring a direct line of descent & ascent for subsequent dives. No need for divers to search for the wreck each time they go down, loosing precious time and running the risk of not finding it in bad viz.

Stewart having done the tie-off, Michael then jumped in to set up the deco rig, a horizontal metal bar hanging 6m below the ship, where divers can perform their last deco stops, breathing surface supplied oxygen.

Dive planning

With recreational diving, assuming you have a dive computer to keep you out of decompression trouble, you can basically just grab a tank, jump in and surface when you feel like it or when your tank is almost empty.

When deep diving however, you can't be that careless. A dive plan is crucial for a safe & successful mission. Once you get into decompression diving, every stop is a virtual ceiling. There's no such thing any longer like an immediate ascent. Unless of course you want to experience your body bubbling like champagne. The effect however is more likely to have you convulse & scream than relax & laugh. So you'd better make sure you'll have plenty of breathing gas for your planned bottom time at maximum depth, more than enough for all the mandatory deco stops on your very slow way back up to the surface and some extra just in case you got delayed.

Any plan should have a back-up. Dive plans are no exception confirming the rule. Issues like exceeded maximum bottom time or depth, loss of gas, inability to return to the ascent line, etc must be addressed beforehand. Leave nothing to chance. Be prepared.

Luckily for me, each dive crew member has his own laptop and I can use anyone of them to plan my dives. Which is pretty cool, as it allows me to play with different dive planning software programs, e.g.: Pro Dive Planner and ANDI Dive Planner. Of these two, I personally prefer the first one.

The programs are pretty straight forward actually. Basically you enter your breathing rate, maximum depth, planned bottom time, bottom & deco mixes and you get a nice table with run times, deco stops & gas needs.

Pre dive preparation

Having a plan is one thing. The right gear to execute it is another. And as for the plan, any life critical piece must have a back-up.


A set of doubles was waiting for me when I boarded, so I just had to screw on my Dive System wings and stainless steel backplate with harness, followed by my two Scubapro MK-25AF regulators. After that I also prepared, analyzed & marked my two decompression stages. Then put all the other stuff in a storage crate: Cressi 'BigEyes' mask, Mares 'Vedra' back-up mask, Suunto 'Viper' computer (gauge mode), wrist slate, Dive Rite primary & safety reel, Oxycheck spool, Buddy & Dive Rite SMB, TillyTec primary & Tektite back-up lights, booties & Mares fins and my 7mm Camaro suit.


All in all about 60kg of equipment... and that's without my Sea&Sea DX8000G compact digital camera. Everything mindfully readied for the dive, my mind itself is next to claim some attention. The danger factor can not be ignored. Anything that goes wrong down there might be fatal. Pre dive stress & nerves. Doubt. Fear for the unknown. Standing on the upper deck, breathing in the fresh morning air, my worries slowly retreat as I refocus on the dive at hand. The sun's high enough now. Mission time!

Deep air dive

The dive deck is spacious enough for four tec divers to gear up simultaneously. But right now it's just Michael and me. We'll be diving together, as it's my first dive of the trip and I haven't been diving deep for a while.

Suited up, double tanks strapped on my back, wings partially inflated, deckhands help me hook up the two deco stages, one on each side. After a last minute check, I duck walk the few meters to the ship's aft platform and splash in. A line runs from the bow to the stern and I immediately grab it, so as not to drift away with the current. Half pulling, half fining I make my way to the bow, where the down line is. This part can be a bit hectic and strenuous due to all the gear and the inevitable drag it causes, no matter how streamlined it is, especially if there're waves and current. But this morning it's not too bad. Still, we take our time at the bow to recover our breath before deflating our wings and start our descent.

↓ 5m. We briefly pause for a mutual bubble check and to pressurize our deco tanks before continuing on our way down. 10m. 15m. 20m. Down. Down. Down.


↓ 25m. Michael's already way ahead, pulling himself effortlessly down without loosing time. Descent time is bottom time. No sense in wasting precious minutes hanging around now. Steadily dropping deeper, I check all my gauges & instruments once again. 30m. The anchor line keeps disappearing into the blue below me. 35m. The wreck's still nowhere to be seen. 40m. Being on air, I can feel the first touch of narcosis. Suddenly, there she is. Just a vague shadow looming out of the blue.


↓ 45m. I pump some air in my wings to slow down my descent. 50m. We're on the wreck. Viz is poor, but Michael knows his way. I follow. It's as if the wreck is shrouded in a cloud of silt. I'm definitely slow-minded narced. I need to double check my instruments just to register what they're showing.


The wreck's alive with hundreds of small fish using it as refuge. Jack fish gangs dart in and out.

It being the first dive, we keep it simple. Staying on the outside, following the wrecks contours, just looking into the larger openings.

↓ 55m. Planned maximum depth. The bottom's maybe another 5m down, but barely visible. There're still some ammunition shells lying there in the sand. But somehow I don't particularly feel like messing around with those.

Soon it's time to return to the ascent line. We've been down for almost half an hour already. Narcosis sure has a way of playing with time. I guess it's because of my mind running at half speed, that time seems to pass twice as fast?


↑ Back at the line, we start on our slow way up. First deep stop's at 36m, where we switch from our bottom gas (air) to our deco mix (nitrox). Up 10m and another short stop. And up again. Then, from 18m onwards, we stop every 3m, holding on to the line to control our depth and avoid being carried away by the current - even though it's only slight at the moment. The narcosis actually sticks quite a while, my head only clearing up totally around 12m, long after I've left the deep!


↑ 9m stop done, we swim towards the deco rig below the ship, move up to 6m and switch to surface supplied pure oxygen to speed up the off-gassing of the nitrogen absorbed by our bodies during the dive. Still, it's a long wait just hanging there. Breathing in and out. In and out.

Time up, I let myself drift towards the ship's ladder, take off my fins and climb aboard. Michael's there already. Having a multi-gas dive computer, he can follow a real time deco schedule, in stead of a max-depth max-time pre-planned one, thus giving him shorter stop times. All in all it took me more than 50 minutes to come up. And that's for a relatively short shallow deep dive, with accelerated decompression.

In between dives

Getting back on board with 4 tanks requires quite an effort actually, but the deckhands are there and quickly help me unload the stages. After which I just sit down and take a couple of deep fresh air breaths before slowly taking off the rest of my gear. My body's still off-gassing. No sense in shaking up more bubbles.


A quick rinse to wash off the salt crystals, a rehydrating cup of water & some food: English breakfast or Thai style lunch. Bring it on! After that, it's truly time for a post dive rest... On the shaded upper deck, watching the sea rolling by, I doze off into yet another world.

Trimix dive

Jamie's found the HTMS Pangan's officers mess and is planning a treasure hunt together with Stewart. Michael's spotted some brass port-holes ready to be hammered out of the wreck's rusted steel hull. My plan is to get further acquainted with the wreck and shoot some pictures of the encounter. The sea's almost as flat as a mirror, reflecting the few clouds in the sky. With a bit of luck the viz won't be too bad. While the crew keeps diving on free air, I decide to go on expensive trimix. After two days of diving on air I'm still getting pretty narced. And while I do think it's a great 'Shadow Divers'-like experience, I would like to remember a bit more of my dives.

Batteries recharged and the camera carefully replaced in its waterproof housing, I'm ready to get seriously wet once again. But first I need to analyse the gas in all my tanks, a precaution not to be neglected without potentially fatal consequences. Satisfied with the oxygen percentage readings, I then suit up and strap on all my gear.

↓ 5m. My trimix being hypoxic, I breathe nitrox for the swim to the down line and for the initial descent, only switching to my trimix back gas around 5m where it's safe enough. Nitrox regulator stowed away, I wet my camera's wide-angle lens, pressurize my oxygen tank's 1st stage and check all my instruments: depth & pressure gauges, dive watch & computer. 10m. Lots of things to think about & do when beginning the dive. 15m. 20m. All the while sinking deeper and deeper, equalizing regularly and monitoring my breathing, as there's a bit of mid-water current and I actually need to pull myself down along the line. 25m. 30m.


↓ 35m. The wreck's already clearly visible, at least for my twilight adjusted eyes, parts of its structure sticking out mysteriously from the silt cloud enveloping it. 40m. Jacks are circling around and around on top of the wreck. 45m. I inflate my wings to brake my descent.


↓ 50m. There's no current on the wreck. Cool. I take my bearings, unhook my camera and head off. Thanks to the trimix, there's only a hint of narcosis - and that probably only because of the task loading. So my head is remarkably clear compared to my previous air dives. And the viz is good enough that I don't need to use a reel. Unleashed, I'm free to wander about at will. Having planned for a max-depth of 60m, there's no risk of me dropping too deep, unless I start digging. Still, I constantly monitor my depth, time & gas consumption.


↓ 55m. The wreck's covered in silt, clams and fishing nets. It's pretty hard to recognize any detail from or object belonging to the old ship. There're plenty of swim-throughs and drop-ins, and this time I do venture inside, keeping in mind that entanglement is a real hazard here.


Every now and then I stop and try to take a couple of pictures. The ambient light however is barely enough for snapshot photography and lots of the shots come out blurry, but some are acceptable and will do as souvenirs.

Soon I've almost used half of my back gas. Time to find the ascent line again.

Having a fixed line of ascent is really a great advantage not to be underestimated. The alternative, a blue ascent with SMB deployment is always a risky business. Currents might take you for quite a ride, requiring patrolling chase boats with an alert crew on the look-out for your SMB. Especially in heavy seas. SMB deployment is an art in itself. If something goes wrong (read: your reel jams) you might end up being jerked up by the buoy accelerating towards the surface. Thereby potentially breaking one or more deco ceilings.

↑ No worries here however as I slowly, hand over hand, climb up the anchor line. Switching to my deco gas as soon as I can. As the current grows stronger in mid-water, all I have to do is release my tight grip just a bit in order to be pushed up along the line like an elevator to my next stop. Cool, but tiresome. Each time I move up I also release some gas from my wings to remain neutral. I try to focus on one stop at a time, not thinking about the total remaining time to surface. Keeping an eye on both my timers. Minute by minute. Staring into the blue. Down the line disappearing into nothing. Watching plankton drift by. A sea snake undulating its way down again after having taken a fresh gulp of air. Changing my grip to avoid tension build up. Watching rising & expanding bubbles from divers somewhere down below.


↑ As my 9m stop comes to an end, I turn around and let the current push me towards the deco rig, making sure I maintain a level depth. With more than half an hour on pure oxygen, it's good to have it surface supplied. Though I do carry an oxygen tank, it's only meant to be used in case of an emergency (read: blue ascent). Surface supplied does mean somebody up there must keep an eye on the supply! With up to four divers decompressing at the same time, even big surface tanks do get sucked empty, in which case a fast switch to a new tank is required. Pure oxygen is strong stuff, so after about 20 minutes I temporarily switch to a lower oxygen percentage for a so called air-break. A couple of squids are hovering nearby. Distracting me from the endless wait.


After almost 90 minutes of decompression, I finally resurface, with a camera full of snapshots. Jamie & Stewart come up with a bag full of china. Michael loaded with a heavy brass port-hole. Mission accomplished. As you can, I hope, tell from the pictures.

Letting go

After the last dive on the wreck, Michael goes down to untie the anchor line & release the M/V Trident. As the thinner drop line was pulled up already previously, he can't use it to come up. In stead, he inflates & lets go of his SMB, so the surface crew can keep track of him during his blue ascent, should he be drifting away with the current.

The M/V Trident by the way has a chase boat at the ready during dives, should the need arise. And a drift line of course trails behind the ship in case a surfacing diver misses the ladder after decompressing.

More wrecks

After the HTMS Pangan, Jamie decides to investigate one of his little book's unknown marks located in the vicinity. On site, the sonar signature promises something big. Local fishermen say it's only a small wooden wreck. Guess who's right.

Too tired from the previous days multiple deep air dives to risk going down for nothing, I decide to wait and see what Stewart, down doing the tie-off, will have to tell. As it turns out the visibility is excellent, the whole wreck visible from 30m, but it isn't too interesting, just an old wooden fishing boat covered in nets. At least at first sight.

However, we're not staying around for a more in-depth exploration, moving in stead towards another nearby wreck, still unidentified, nicknamed Big Boy.

Big Boy rests in peace entirely below 55m, too deep for my camera. Not that it matters, the viz is so bad I feel compelled to use my safety reel so as not to get lost. Orientation remains difficult though. I'm not even really sure where I am on the wreck. I let myself drop down to 66m, before heading up again and reeling my way back to the anchor line. None the wiser. But then, it usually takes quite a few dives to get a feel for a new wreck.


During my last stop, I witness a trevally doing an apparently crazy bubble eating dance, but it turns out it's actually being pulled up by somebody on the ship and fighting for its -literally- expiring life.

Aboard the M/V Trident, the crew's indeed fishing. And giant trevally are biting one after another.

Return journey

As we head back towards Koh Tao, the sun slowly sets. For me, it's been a great trip and a lifetime experience.

Risks & dangers

Both deep and wreck penetration diving require specialized training. Each has its own particular risks and dangers. To mention but a few: nitrogen narcosis, oxygen toxicity, carbon-dioxide build-up, gas mix-up, out-of-gas, decompression sickness and silt-out, disorientation, entanglement hazard, brass-fever, structural collapse, equipment failure, etc.

Deep wreck diving indeed is not without risk. People die. No matter their experience level.

On the trip before mine, an experienced closed-circuit-rebreather diver died. Another diver, on open-circuit scuba, got badly bent trying to save him. Luckily, despite the Thai navy's helplessness, he got away with it after several hyperbaric chamber treatments.

My own trip got cut short when the other paying trimix diver got lightly bent, even though he'd followed his dive plan. For twelve hours, most of them breathing oxygen, he had to lay down, convulsing in pain each time the decompression sickness waves hit him, until he got to the hyperbaric chamber on Koh Samui. Luckily for him, one five hour treatment was enough. Followed by a shorter one for good measure just in case. After which he felt like nothing had happened.

I myself got some 'niggles', deep divers jargon for decompression stress, in my left fore-arm, probably due to the strain of holding on to the line in strong mid-water current, preventing normal off-gassing. A bit more and it would have been decompression sickness too. Requiring hyperbaric treatment. Live & learn, as Michael would say.

That said, I consider my daily bicycle trip to & from work, 5km through the Copenhagen city traffic, as a dangerous activity too, not to say a hazardous enterprise, considering the frustrated, aggressive & irresponsible behaviour of some automobile drivers. Indeed, in the traffic too we venture in an environment we do not fully control, in conditions we do not fully master. But it doesn't stop us from going out there!

DIR?

If you have a very set way of doing things, whether it's DIR or not, you should definitely check with the dive operator beforehand that your demands can be satisfied. But even if you have a more flexible approach to things, it's a good idea to check that you can live with the dive operator's way of doing things.


I mention this because things are not that standard when it comes to deep diving. The three places I've tried it so far: Egypt, Philippines & Thailand, each have their particular way of setting up gear, planning dives, using bottom gases & different deco mixes.