Unknown submarine wreck from World War II discovered

Revealed by camera

The wrecks they had found earlier on the cruise on board research vessel G.O. Sars, were clearly visible structures on the detailed map the researchers from IMR and NGU use when they plan where to set up locations. 

"After examining the wreck using a camera, we could quickly establish that it was a submarine", says Bakkeplass.

While the others on board continued the work of investigating what species live on the seabed in this area and what it consists of, Bakkeplass began looking for information about the submarine.

"Since there was no sign of any wreck right here, I checked if there were any submarines that were missing in the area and that could match this wreck."

Two missing submarines

After various possibilities had been examined and experts consulted, including both the Norwegian and British navies, it became clear that it was a British submarine.

But exactly which submarine was still uncertain. It could be one of two: HMS Oxley or HMS Thistle. One sunk just before World War II and the other during.

"Based on the photos, it was established that it was a British submarine, and available information could indicate that the wreck of HMS Oxley was closest", says Bakkeplass.

After they got ashore and contacted submarine experts, the maritime museum, and professionals, however, HMS Thistle became the more likely option.

"After several people had studied the photo, we concluded that it was probably HMS Thistle, but the photo showed too few details for it to be conclusively settled".

A second cruise identified the HMS Thistle

The opportunity to identify the wreck arose when the MAREANO-programme set sail for their research cruise in October. 

Before the actual mapping can start, the equipment must be tested. It is done before arriving at the dedicated mapping areas. This time the researchers were to carry out investigations in the Skagerrak, and thus the RV G.O. Sars passed the submarine wreck on its way south.

"In advance, we knew what characteristics we should look for; thus we were able to identify the wreck as “Thistle”, but with a small caveat that it is the Royal Navy who is responsible for the final identification", says cruise leader Kyrre Heldal Kartveit.

After the wreck had been examined, the RV G.O. Sars set course for their preplanned research locations.

"We will map parts of Skagerrak where there is partly challenging terrain with steep slopes and deep underwater valleys so that we can draw a representative map of what is on the seabed in these areas – before it's possible to either establish administrative management units or industries here.

War grave

About HMS Thistle's last voyage we know that it ended on 10 April 1940. It was then sunk by a German submarine. None of the 53 crew members survived.

"At that time, navigators used bearings and squares and not GPS as they do today. This means that the position for the sinking is inaccurate", says Bakkeplass.

As for HMS Oxley, it was mistakenly sunk by another British submarine. Two of the crew survived, while 53 perished. Here, too, it is partially unknown where the submarine sank. In addition to the uncertainty about the last surface position, it is impossible to say anything about how far the submarine drifted from the time it was sunk until it ended up on the sea bottom.

Now HMS Thistle rests at a depth of 160 meters outside Rogaland in south-western Norway. Since it is a submarine that was sunk during war, the vessel is to be considered a war grave. According to maritime law, The British Royal Navy maintain right of ownership.