Divers find sunken World War II-era submarine off Phuket coast

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Divers find sunken World War II-era submarine off Phuket coast

September 11, 2020 - 01:03

Press Release

8 September 2020, Singapore - USS Grenadier (SS-210), a submarine which was scuttled more than 75 years ago while under attack and surrounded by Japanese aircrafts and ships during World War II on 21st April 1943, is suspected to be found by a group of technical divers in October 2019.

The finding is believed to be a tambor-class submarine which was the United States Navy's first fully successful fleet submarine.

The team of divers are waiting to get this finding verified by The United States Naval History and Heritage Command. They used their own Singapore-registered yacht to find the wreck.

“It is every technical diver’s dream to find a piece of history. We train a lot for these challenging dives because we like to explore and find what is not easily accessible. This is our first time making such a discovery but we are searching for other shipwrecks too,” said Lance Horowitz.

Lance is part of the team of four passionate technical divers that located the shipwreck. It is lying 80+ meters underwater and about 80 nautical miles south of Phuket, Thailand. The divers managed to locate this shipwreck with a side-scan sonar, a device which allows them to capture images of the seabed from their vessel.

The four-men team, Jean Luc Rivoire, Ben Reymenants, Lance Horowitz and Benoit Laborie took six dives over a period of six months to try and identify the submarine. 

Jean Luc Rivoire and Benoit Laborie are currently based in Singapore and have been living here for approximately nine years. Ben Reymenants and Lance Horowitz live in Phuket.

They also searched the archives of twelve countries such as USA, UK, Germany, Japan, Italy and Netherlands involved in WW2 with submarines, for all potential vessels reported lost and not yet found in the Strait of Malacca. It led to three possible lost submarines. The description and dimensions seemed to match the USS Grenadierperfectly.

The team took measurements of various parts of the lost submarine such as the conning tower, hatches and capstans. These measurements were identical to technical drawings of the tambor-class submarine, obtained from the United States National Archives and Records Administration. 

“Ben gathered a set of coordinates from various sources, mainly coming from fishermen. The local fisherman would often lose their nets while fishing on these spots, which can be natural rocks or artificial reefs such as shipwrecks. Our boat is equipped for such a search and for days we patiently scanned all coordinates until we saw a shape on the sonar screen! We could not dive into the site straightaway because of bad weather conditions and strong currents. It requires a fair amount of planning. Some of the risks diving 80 meters deep on a wreck with low visibility are entanglement or not finding the line back to our boat at the surface and drift away in the current still having to do the long decompression stops. After six dives on the shipwreck, we are now 95% confident that this is the USS Grenadier,” added Lance.

The expedition required them to factor in tides, strong underwater currents and to use special equipment such as closed circuit rebreathers (CCR), Diver Propulsion Vehicles (DPV) and mixed gases including helium for long decompression dives of several hours.

The shipwreck lies upright on a sandy seabed, 83 meters underwater, partially covered by fishing nets. 

“We could not find a plaque with the name of the ship, because the topside "skin" (outer hull and fairwater) of the submarine has been eroded and probably torn off by the nets and the anchors of fishing boats, leaving the pressure hull exposed,” said Ben Reymenants.

The team also found the hatches fully opened which is a sign that the ship was deliberately sunk and is coherent with historical accounts of the survivors.

The divers also found an electrical part, a resistor. It shows an inscription with the name of a Chicago-based company which has manufactured electrical parts for more than 90 years and used in navy vessels.

The divers are refraining from disclosing the wreck's precise location because of the extensive looting for scrap metal that takes place on historical shipwrecks in the region. Furthermore, they are cooperating with the relevant government agencies and following their guidelines about war heritage sites.

"It is thrilling, when you arrive at the bottom of the ocean, in the middle of nowhere and you start to distinguish the massive silhouette. It then comes to mind the history attached to it and being lucky enough to be the first one to approach the submarine since it sank more than 75 years ago. It is a truly powerful feeling," said Jean-Luc Rivoire.

The divers are planning more trips to the shipwreck. “A lot more remains to be explored like the guns, the torpedo tubes and the periscopes, we hope to definitively identify it, bring some closure and honor the memories of the war heroes who served on this ship,” added Ben. 

For more information on the team’s dives, visit their Facebook page.


About USS Grenadier (SS-210)

USS Grenadier (SS-210), a 94m long Tambor class submarine with 76 sailors on board, was in pursuit of two enemy ships off Phuket when it was hit by an enemy aircraft on April 21, 1943. After 15 hours of trying to make repairs, stranded on the seabed, 80m deep, they managed to regain buoyancy and rise to the surface. However, the motors were too damaged and the ship could not move. The sailors noticed enemy ships on the horizon and were forced to scuttle Grenadier so that it would not be seized by enemy forces. They swam at the surface until all hands were picked up by an Japanese armed merchant ship and taken to a commandeered catholic school in Penang, Malaysia then to prison camps in Japan. Held prisoners of war, the crew members endured 28 months of torture resulting in the illness and death of 4 sailors.

In his book “Threshold of hell” (1985), Albert Rupp, the youngest sailor aboard the USS Grenadier who was 16 years old says,“ A twisted body on the ocean floor, a heap of wreckage for sure, a ship that even until today, her crew still adores. You’ll live again, of fateful ship through those who knew no fear. We’ll carry the fight until the end for our beloved Grenadier”.

About the team

The team comprising Jean Luc Rivoire, 50; Ben Reymenants, 47; Lance Horowitz, 36 and Benoit Laborie, 42 is agroup of four passionate technical and cave divers from France, Belgium and New Zealand. They are nowadays based in Singapore and Phuket. They have been diving for many years around the world in deep water sites and challenging environments such as Florida caves or South East Asian caves.

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