The Unicorn

The Unicorn a.k.a Hishidaiya Maru a.k.a. The ‘Dog Food’ Wreck

Written by Stephen Burton

(near Koh Tao, Southern Thailand)

Depth 52meters ; Technical decompression diving only

The Koh Tao dog food Wreck 'The Unicorn' Sketch courtesy of Jamie MaCleod at MasterTec, Koh Tao.

Details of Sinking:-

This Vessel sank around 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. 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!

Wrecks details

The wreck is that of a large modern 1960-70’s, 60meter 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 60degrees(Not shown correctly on the sketch) with the top of the bow at 38meters, 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 available for technical divers highly experienced in diving in conditions where a total silt-out may occur. Needless to say a penetration line is absolutely necessary when entering the deep refrigerated holds or any crew-ways/machinery rooms. 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.

Update to the wreck survey history July 2012

This update by Ib Ottesen

I was together with Jørgen Lundbaek, Dusty Rhodes And William Stevens, the first diver on the wreck, hired by the insurance company to find the wreck and establish the nature of the cargo.

We did NOT dive under armed guard. The was only us 4 divers and the owner of the wooden tourist boat we had sailed down from Pattaya.

The cargo was ALL canned tuna fish marked “Pet food only” there was NO dog food on board. The manifest had the cargo listed as “Canned Tuna fish” however for human consumption. Therein was the insurance fraud.

According to the villagers, the vessel dropped anchor. The crew took their time transferring stuff to the Island, before a loud explosion in the stern area was heard caused the ship to sink.

News on this Wrecks condition-March 2003

This description courtesy of Mr. Jamie Macleod, March 2003.

The wreck is completely intact, nets that obscured the wreck have now been cleared from most of the penetration points. All penetration is very tight, only room for one diver, and very silty. A diver’s discarded deco tank, twice it’s diameter with encrustation complete with antique J-Valve and Dacor first stage swivel reg was found on a recent dive. The owners bones were nowhere to be seen.

Visibility has been very good lately, 10- 15 m on the deck, 5m on the bottom, but that’s as good as gets , average is 5-7m on the deck, 2 m at 50m.Always clear water (20m + from the deep stop up)

Two huge grouper get very shitty when you go inside, and a group of the biggest red snapper in the world buzz you all the time. Big schools of jacks and barracuda patrol the area directly above the wreck.

News of the wrecks condition-August 2004

This description courtesy of ‘Andy’ at Big Blue Tech Samui

I did the Unicorn for 3 days straight a few weeks ago on my Russian CCR. It was nice to have enough time to really check it out. Found a Frog fish and some Trumpet fish I have never seen in this area before. Other wise shit visibility and tons of nets…

June 2008 Update

A skeleton has been found in the wreck by diver ‘Peter’ from Master Divers.
The Thai Navy are making plans to cut him out the wreck.

Pattaya Mail Newspaper logo

Story Courtesy of PattayaMail Original story link =

Navy divers discover skeleton in wrecked freighter

Remains believed to be those of missing German diver

Patcharapol Panrak

A human skeleton believed to be that of a missing German diver has been found by Royal Thai Navy divers in the engine room of a Unicon freighter that sank during Typhoon Gay nearly 20 years ago.
The Navy was using the sunken vessel to train divers to operate at depths of up to 100 meters when the remains were discovered. They are thought to be those of Tomas Casagrande, a German diving instructor who disappeared in 2006.

Navy divers have discovered a skeleton, believed to be that of a missing German diver, in wrecked freighter.
Rear Admiral Narongpol na Bangchang stated on June 5 that the Naval Ordinance Test Station at Sattahip was training divers at the wreck of the freighter, eight nautical miles off Koh Tao, near Koh Phangan in Surat Thani Province.
He said that Capt Anupong Itsarangkul na Ayutthaya, operator of the Naval Ordinance Test Station, along with Lt Chaiwut Iamsamai and Lt Mongkol Podaeng, both operations trainers, had been cooperating with German divers to search the wreck, which was resting at a depth of 51 meters, to find the body of their missing companion, Casagrande.
Casagrande had been a diving instructor with the Levy John Locker Company on Koh Tao. The Germans said he had disappeared on February 23, 2006, while diving on the wreck.

The Navy divers had modified their training plan to search for the body. The depth of the wreck had made the work difficult, but they found something that looked like a human skeleton in the engine room.
Rear Admiral Roengrit Bunsongprasert, director general of the Naval Civil Affairs Department said that the German Embassy in Bangkok had submitted a letter to Admiral Sathirapan Kaeyanon, commander-in-chief of the Royal Thai Navy formally requesting the removal of the body from the freighter.
The Navy approved a 24-member operational team, including a physician, and the group traveled from the Naval Ordnance Test Station on June 6 with a high-pressure chamber and other specialist equipment loaded on the HTMS Manklang, sailing out of Laem Tian Port at Sattahip Naval Base.

The diving work was undertaken in cooperation with Jamie McLeod and Kevin Morgan, who had been friends of the missing diver.
Rear Admiral Roengrit said that reports from the site indicate work was proceeding and that it was likely a gas cutter would be used to enlarge the entrance to the engine room, which was a difficult place to enter. The mission was due to be completed by June 16.
Typhoon Gay formed in the southern Gulf of Thailand on November 1, 1989, and was the worst typhoon to hit that area in 35 years. By the time it dissipated over the Western Ghats in India on November 10, at least 500 people had lost their lives.

GPS Location:-

Just North off Koh Tao “Mango Bay” at WGS84 N10’9.699, E099’50.929 (Thai Navy Positions…)

Last dived by:-

Jamie Macleod diving from the MV Trident Tel:- 089-591-3186

James Thornton-Allan at Big Blue Tech Tel:- 084-440-8005