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Big Blue Tech - Koh Tao - Thailand                                                             Facebook  Twitter  GooglePlus

HTMS Sattakut

The HTMS (His Thai Majesty Ship) Sattakut has everything, history, eerie-ness, marine life in abundance, penetration points with natural daylight, penetration points with no natural daylight, and depths up to 30 metres.

It was originally a landing craft infantry vessel commissioned by the US Navy in 1944, and was involved in three battles in World War II; the liberation of the Pilau Islands, the battle of Okinawa, and the battle of Iwo Jima. 

In 1946 the US Navy decommissioned it, and it was purchase by the Royal Thai Navy. It lived out its service as a patrol boat, until they decommissioned it in 2011. Shortly thereafter, the Thai Department of Marine and Coastal Resources (DMCR) purchased the ship with the intention of donating it to Koh Tao to act as an artificial reef, in order to promote tourism. The vessel was stripped of it's engines, furniture, electric cabling and thankfully it's ammunition! After being cleaned and sent to Koh Tao, it was sunk on the 18th June 2011.

Unfortunately because a storm came in as it was being sunk, it ended up on its side in the middle of a channel; hardly an ideal location. So in July a salvage team was brought in to right the vessel and move it to a more suitable location. 

It currently sits upright in around 30 metres of water, with the bow facing roughly North.  The location is perfect, as it sits around 10 metres to the South of a dive site called Hin Pee Wee. This has obviously helped to bring marine life to the wreck, which is evident today- all over it! There is currently a huge Jenkins whip ray that lives underneath the hull. There are huge spotted snapper and giant groupers sheltering from the current near the conning tower, and if you have good eyes you will be able to find some Jan's pipefish in the rusting railings. Moray eels also like to find places to sit and watch the underwater world go by. For those that want to venture inside, apart from disturbing a number of giant groupers from their hiding places, you will see lots and lots of shrimp.

The vessel is perfect for conducting technical training dives on. For the TDI advanced wreck course there are many places on the main deck to practice reeling skills and teach communication in simulated no-visibility. Plus, there are numerous places to penetrate the wreck, and they vary greatly in terms of how quickly and how badly they silt out, so practising exits in zero visibility can be made progressively more challenging. The wreck is also a great place to conduct TDI decompression procedures training dives, as there are plenty of reference points to use when ascending to meet run times, undertaking deep stops, and gas switching.

But it's not all about training. Lets not forget that this wreck has an amazing history, and sometimes it's just great to go for a long deco fun dive around it, or a penetration fun dive inside it! The ship is the closest dive site to Big Blue on Sairee beach, and we use it a lot!


The Unicorn

This cargo essel sank during a typhoon in 1989. Local Koh Tao inhabitants said that the ship just pulled up off shore, around a mile North of Koh Tao 'Mango Bay' and over the next couple of hours slowly sank. No-one was hurt in the sinking, and an insurance fraud was immediately suspected.

A commercial Diving company was hired by the vessels insurance investigators to investigate the cause of the sinking and to confirm the cargo. which was listed as expensive Tuna Fish. Divers descended to examine the wreck, and discovered that the holds contained nothing but low-grade animal Feed (Dog-Food) un-fit for human consumption, NOT expensive Tuna fish as listed on the manifest!

The wreck is that of a large modern 1960-70s, 60 metre long steel freighter lying stern-down on the bottom at a depth of 50m. The vessel leans slightly on its port side an angle of 60 degrees, with the top of the bow at 38 metres, and the keel of the bow area several meters above the seabed, allowing divers to swim under this area of the hull. Lots of penetration points were available when it originally sank for technical divers highly experienced in diving in conditions where a total silt-out may occur. But nowadays it is considered too dangerous to even attempt to penetrate.

By way of warning, there have been a number of serious DCS injuries to even experienced recreational scuba divers who have attempted to dive this wreck without proper 'technical diver' training. One French couple having got completely disoriented in a narcosis enhanced 'black silty cloud of death' ran out of air and bolted to the surface...missing all their deco. One of this 'buddy pair' suffered severe DCS which did not respond to treatment is now languishing paralyzed in a wheel chair back in France. The wreck when first discovered was covered in several large fishing nets which have all since been removed by local tech divers.

MV Trident

The stories surrounding this great old boat all contribute to how important she was and is to Koh Tao wreck diving. During her service, she located other wrecks – the most notable being USS Lagarto, a naval submarine, which became the basis for a movie – and allows Koh Tao divers of today to train or enjoy many wonderful and exciting wreck diving trips in the Gulf of Thailand. It is said that the MV Trident enabled her crew to locate more than one hundred wrecks around different locations in the Gulf of Thailand. She went out with wreck divers and technical divers for days or weeks, effectively working as a liveaboard diving boat for highly-experienced scuba divers. It has also been reported that some of the methods used to locate deep or difficult-to-find wrecks included paying local fishermen for co-ordinates of where nets have been lost.

Her deliberate sinking in September 2010 came after great teamwork and fund-raising by those who want to preserve Koh Tao wreck diving, and even allow it to flourish. For those starting to get excited about exploring a wreck off Koh Tao while only having a PADI Open Water Diver or Advanced Open Water certification, they can stop right now. This Koh Tao wreck is too deep for that kind of diving. Luckily, though, just nine months after the MV Trident stopped at her final resting place on the seabed, yet another Koh Tao wreck was deliberately sunk, creating an artificial reef for marine life and PADI scuba divers of most levels. This much shallower wreck is known at HTMS Sattakut, and receives regular visitors just off Koh Tao's west coast. There is also a small wooden wreck at the very shallow Japanese gardens dive site.

MV Trident is located just off the south-east part of Koh Tao, a short distance to the direct south of the well-known and often-dived Shark Island. This is at a thin pinnacle which creates Ao Hin Ngam (Hin Ngam Bay). As already mentioned, the wreck diving site of MV Trident is in water that is too deep for Open Water or Advanced divers. In addition, there's nothing much else to see above the wreck, which is at approximately 28 metres, depending on tides, at its shallowest point. To further dissuade PADI divers without the experience or qualifications, the penetration points (places for wreck divers to enter) are limited in both size and number. Finally, the currents down here are often medium to strong, although it is possible to catch the tide just right and enjoy very little current.

These currents and the lack of divers work to benefit the amount of healthy marine life at MV Trident. Lots of nutrient-rich water passing the wreck brings food for the huge amount of fish and invertebrates who call it home. The schools of predatory fish such as barracuda and travelly are not scared off by constant human activity and can therefore enjoy a prosperous life below the waves.

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