The PAK 1 has a long an fascinating history. She started life in Japan, working as an LPG tanker and was later purchased by PAK Line Co., Ltd in Thailand. In the early hours of August 25, 1996 she encountered a storm near the Cambodian border while on her way to Vietnam from Sriracha. She sank quickly, taking most of her crew with her. 

A local dive center was quick to investigate, and found the PAK 1 in 60m of water, vertical, with her bow just below the surface. She remained vertical for nearly 6 years and became a major tourist attraction. As time went on she began to rise out of the water and drift, creating a shipping hazard. The Royal Thai Navy set out to sink her properly, and was eventually successful. 

The PAK 1 now lies off the coast of Rayong in 42m of water. While she is not the world-famous vertical wreck she once was, she’s still a fantastic wreck with something to offer for everyone.

Schematics of the PAK 1

Diving the PAK 1 Wreck

The PAK 1 is a ghostly wreck. Covered in nets and often shrouded in poor visibility, it can take a few dives to sort her out in your head. On descent the superstructure peers out from the green, soupy thermocline. 

She’s just out of range to be dived as a day trip, so unless you want to leave at 5am and return at 11pm, you will likely be sleeping on a boat. Dive operators have long since taken her off their itineraries and you can expect to have to deploy your own shotline. This is a proper Gulf of Thailand offshore wreck.

Buoy Line for Descent & Ascent

There is no buoy on the PAK 1, you will need to locate her yourself and deploy a shotline. Currents are not something she’s known for, but they do occur. Due to her remote location, poor visibility, and the possibility of currents, most divers deploy a sturdy shotline, secure it properly, and maintain physical contact with this line for all descents and ascents.

Nets & Hazards

The PAK 1 is a relatively large wreck and is covered in nets. Add in some nitrogen narcosis and poor visibility, and you have a recipe for getting lost. Divers are then faced with a choice: continue searching for the shot and blow the dive plan, or execute a free ascent with drifting deco. Many divers run a continuous line from the shot while navigating the PAK 1.

The PAK 1 is relatively stable, but few have ventured inside in recent years so there is little knowledge of the state of her interior.

Visibility

The thermocline runs at around 25-35m on the PAK 1. Below the thermocline you’re looking at 3-5m visibilty. Above the thermocline things get much nicer, with up to 30m+ visibility. 

Areas of Interest & Penetration

The PAK 1 has a lot going on, but with all the nets and the vis, half the fun is just figuring out what part of the ship it is that you’re looking at. 

Drawing by Steve Burton of thaiwreckdiver.com

Bow

The substantial damage to the bow from her impact with the Royal Thai Navy ship is quite interesting. Beware of nets hanging over the gunwale. There is a small penetration point here in the bow that has yet to be recently explored.

Cargo Hold

The former home of the LPG tanks, there’s still some machinery and such to be found.

Superstructure

The superstructure will often extend up out of thermocline, offering some stunning views. Much is still intact, and there are some hatches that have some promise for penetration. 

Stern

The rudder and props are still intact. If you have the time they are worth a visit. The stern is rather beat up from her years bouncing off the bottom as the vertical wreck.

Experience & Training

This is a fantastic wreck for anyone interested in or experienced with decompression diving and wrecks. For many of us, this was our first proper off-shore wreck. She’s just enough of an adventure to offer some excitement, but accessible enough that you can actually get a decent dive even with a recreational deep specialty. And of course, CCRs, trimix, and penetration training can be put to good use on the PAK 1 as well. There really is something for everyone here.

Logistics 

This is a full-on Gulf of Thailand wreck. There are very few dive operators that will go here, and you’ll probably need to sleep on the boat. It’s easier to find overnight, deep-sea sport fishing boats for trips like this. You will most likely need to bring all of your own equipment including gas, shotline, etc.

Staging Tanks

Most divers on the PAK 1 stage their tanks only when they use a continuous line back to the shotline, and even then many will opt to carry their deco tanks with them in case they need to abort and execute a free ascent with drifting deco.

Running Deco

Teams usually plan on running deco on the shot line. A free ascent with drifting deco is usually avoided, as surface currents can push teams kilometers apart, especially with longer deco runs.

Penetration

The PAK 1 doesn’t have a ton of penetration available. Currently there are 2-3 known points of interest that show potential, but they have yet to be explored in greater detail in the last decade. In the past it was reported that you can access the bridge, crew quarters, and engine room from the superstructure in the stern. It is not known if this is still possible. Recently, another penetration point was found in the bow, but this has yet to be explored in recent times.

History of the PAK 1

She was laid down in Japan in 1971 as the Koho Maru V. Some years after she was purchased by PAK Line Co., Ltd, a Thai company that intended to use her to transport natural gas between Vietnam and Thailand. It was then that she received her new name, either the PAK 1 or the Pak Wan depending on who you ask.

On her final voyage, the PAK 1 docked at the Esso gas depot in Sriracha and loaded her tanks. She then steamed east towards Vietnam, headed for the port of Vang Tao. Some time in the early hours of August 25, 1996, tragedy struck.

The PAK 1 Sinks

One of the crewmembers was eventually tracked down at Samut Prakan port by Khun Po of the now defunct whalesharkthai.com in 2002. The crewmember reported that a week before the sinking he heard a loud noise in the engine room. Water began to flood from the propeller into the 1st, 2nd, and 3rd ballast rooms, but the 4th and 5th in the bow remained sealed.

On the night of the incident a week later, most of the crew lay in the cabins in the stern of the ship, except for the survivors who stayed in the bow area. At 3:00, a loud explosion was heard in the stern, and the PAK 1 quickly began taking on water. The crew acted quickly, first rushing to the forward LPG tank to empty it and avoid an environmental disaster. The forward tank was reported to be half empty, and the aft tank full. Their efforts were in vain, however, and they abandoned ship and made for their lifeboat. 

With limited supplies, they ran out of food and water after four days. As hope waned, on the seventh day they were found and rescued. Sources differ on the crew size and the number of survivors, but around 8-10 crew members perished and 2-4 survived. 

The Royal Thai Navy mounted a search and recovery effort, and rumor has it that they found the wreck only after smashing into it at flank speed.

The Vertical Wreck

Soon after the sinking hit the news, a local dive center heard rumors of a new wreck and quickly set out to investigate.  

They found the PAK 1 in 60m of water, vertical, the bow just 5m below the surface, with stunning 50m+ visibility. They noted substantial damage to the bow. 

She became known as the vertical wreck, and divers from around the world came for a dive. Engineers assessed the tanks. At 25mm thickness, they estimated that they would hold for over 20 years, and over time gas would escape and she would slowly sink. For years she remained vertical, her stern in the sand and her bow just below the surface. 

Just over four years after her sinking, things began to change. In December 2001 and January 2002, divers reported a large amount of LPG being released from the tanks with a constant stream of bubbles rising to surface, creating a noticeable smell on the surface. 

In February 2002 she lifted off the bottom and went on the move.

With more than 600,000 liters of LPG, the Royal Thai Navy became increasingly concerned as she drifted in and out of commercial shipping lanes.

With her bow now 6m out of the water, she became an even more interesting dive site. Those who were able to dive the PAK 1 in this era were treated to a rare and incredible sight, to dive down to 50m under the stern and look up through the propeller and rudder and look up the whole length of to keel all the way to the surface. 

The Royal Thai Navy Sets Sail

The Royal Thai Navy was alerted to the danger by a Wichien Singtothong, a dive operator in Rayong. A helicopter was sent to find the PAK 1 who reported that she had indeed risen above the surface was had moved from her original location. 

Royal Thai Navy Patrol Boat 214 was then deployed with a team of divers to further investigate the issue, and again confirmed that the bow was out of the water and that gas was leaking from the tanks. An operation was planned to created a floating lighthouse on the wreck to warn other ships, but the danger of an electrical spark and the leaking gas caused some concern.

In the early hours of March 3rd, 2002, Admiral Oknit Muensri led a small armada, including the HMS Sukhothai, HMS Udomdech, HMS Rad, HMS Samaesan and HMS Petra. He commanded five warships, over 300 sailors, and 25 navy divers. But the PAK 1 would not go down without a fight.

Each ship in the armada played their own role in the operation.The HMS Sukhothai was to keep watch for other ships and ensure they stayed a safe distance away. The HMS Rad and the HMS Samaesan would act as glorified tug boats and tow the PAK 1 north. The HMS Udomdech was the medical ship, on hand with a decompression chamber to offer assistance to any divers that encountered issues. The divers and demolitions experts would operate off of the HMS Petra.

After 7 hours at sea and 178km steaming, the Royal Thai Navy found their target.

Towing the PAK 1 to Safety

The Navy’s first goal was to tow the ship closer to shore, seeking shallower water between Koh Samet and Koh Chang. Efforts began soon after the fleet’s arrival on March 3rd, 2002, as Navy divers loaded their RHIBs with 300m of 6in cables and other equipment needed to tow the PAK 1. The fleet remained upwind, as the 100m area around the wreck was considered a safety hazard due to the LPG fumes.

Navy divers left the HMS Petra and descended to 50m and attached cables to the PAK 1, which were then attached to the HMS Rad and the HMS Samaesan. Once secure, the PAK 1 embarked on her final voyage, north, at a speed of 1.5 knots. 

After 32 hours and 185km, the PAK 1 was in position.

Plan A: Try to Flood the Tanks

Now that the PAK 1 was in shallower waters, the plan was to attach the towing cables from the HMS Rad and the HMS Samaesan to the PAK 1’s gas piping and rip them out. The idea being to empty the tanks and finally sink the PAK 1. The 20in gas piping however was too strong for the cables, and they snapped.

Plan B: Try to Flood the Tanks, Again

Undeterred, Navy divers descended to reattach the cables to the gas piping. The HMS Rad and the HMS Samaesan steamed ahead, and the cables snapped, again.

Plan C: Use More Cables

With a new plan, the Navy divers descended a third time, this time attaching four cables to a single gas pipe in a final attempt to dislodge it. The cables snapped, again, and the Navy took the rest of the night to rest and head back to the drawing board.

Plan D: Blow Up the Tanks

On the morning of March 6th, 2002, Admiral Oknit stood on deck and surveyed the PAK 1, which now sat 16m above the surface. The mighty tanker that spent the last six years of her life as a shipwreck now openly defied a fleet of Royal Thai Navy warships, whose efforts so far have only proven to lift the enemy ship further out of the water. 

Admiral Oknit ordered the Navy divers to descend and place blocks of C4 at four strategic points on the ship. At 10:33, sailors performed a religious ceremony to pray for the spirit of the sailors lost on the PAK 1 and to raise morale. Admiral Oknit then depressed the detonator button, and… nothing happened.

Plan E: Blow Up the Tanks, Again

Navy divers once again descended on the PAK 1 and once again rigged the tanks to blow. Another ceremony was performed and at 12:57, Admiral Oknit depressed the detonator. Much to his relief, there was an explosion. Unfortunately, this released an enormous amount of gas, irritating the lungs of everyone in the vicinity.

Navy ships immediately fled the area to 18km upwind, to escape the noxious fumes and stay clear of a feared secondary explosion. As they waited, the PAK 1 defiantly lifted further above the surface, now 30m out of the water. After 5 hours, Navy divers descended on the wreck to assess the situation. 

They found that only one of the charges had exploded, releasing one of the LPG tanks and damaging the other. They also found that the gas was reacting with the water, causing their skin to erupt in rashes. They aborted their dive to receive medical attention. 

Plan F: Let’s Try Cables, Again

The salvage team’s new plan was now actually just the original plan. Over 15hrs after the mostly unsuccessful explosion, Navy divers once again descended onto the PAK 1. This time they attached cables to the remaining tank, and after considerable effort were able to pry it loose. The LPG tanks were later used by the Royal Thai Navy as target practice for their new Exocet missiles, which met a similar fate as the Liberty wrecks and the Sarasin.

The PAK 1 finally sank, resting upright in 42m of water. Navy divers made their final descent onto the wreck to look for the 9 souls they believe to still be inside. None were found.

“The Navy has done a magnificent job.”

The operation to sink the already sunk PAK 1 took more than 120hrs and cost 2.2m baht. The Royal Thai Navy considers this to be one of the toughest jobs that they have ever undertaken. A navy spokesman released a statement saying “The navy has never salvaged any ship more than 60 meters. Considering our limited budget, equipment and know-how, the navy has done a magnificent job.”

Other Wrecks in the Area

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