High-tech 3D image shows doomed WWII Japanese subs 2,600 feet underwater off Hawaii

High-tech 3D images and video showed two doomed WWII Japanese submarines 2,600 feet underwater off Hawaii.

Nonprofit group Ocean Exploration Trust explored the wreck of Imperial Japanese Navy submarines I-201 and I-401 off the coast of Oahu and posted an image and video from the exploration Thursday on social media. 

The expedition on Nov. 3 and 4 was led by the Nautilus Live team, funded by the Office of Naval Research and commanded by Dr. Robert Ballard, who found the Titanic wreckage in 1985.

The body of the I-201 Japanese submarine "has not been viewed for the past 14 years," said the narrator of the video footage. In 2009, the Hawaii Underwater Research Lab found the I-201 submarine, and the team returned to "examine changes in these sites since their last survey." 

Commissioned in February 1945, the war ended before the submarine could carry out an operational patrol, said the Hawaii Underwater Research Lab. At the end of WWII, the high-speed submarine was surrendered to the U.S. Navy and "intentionally scuttled" off the south coast of Oahu. 

Using the K2 High-Resolution Mapping System with the Norbit multibeam echosounder, explorers aboard #EVNautilus created this three-dimensional image of I-201, a high-speed submarine built for the Imperial Japanese Navy during #WorldWarII. It rests 800m deep south of #Oahu. pic.twitter.com/sFeLWJOtft

— E/V Nautilus (@EVNautilus) November 4, 2023

Video posted on social media showed some fragments of rust but the submarine was still relatively intact despite the amount of time underwater. Footage showed the Japanese rising sun flag on the submarine and the identification I-201. Wires were shredded across the 19-foot hull, and up to 52 people could be wedged into the submarine, which had plenty of length but not much width.

The submarine carried 10 torpedoes in the forward section and had two periscopes. Video shows a torpedo resembling a "Nerf gun" lying on the sandy bottom near the submarine. A propeller was visible at the back end of the torpedo. 

The video also showed the wreckage of another submarine, the I-401, which was a 400-foot submarine, and the largest submarine ever built. It remained the largest until 1965, when the U.S. built the Benjamin Franklin, according to Nautilus Live. The hull of I-401 was damaged compared to the I-201 but the submarine's metal was still really shiny. There were guns on the deck of the submarine and was an "instrument of destruction."

Submarines played a huge role in WWII. Japan's Imperial Navy built submarines faster than any other country in the world, according to "Japanese Submarines in World War Two," a book published by the U.S. Naval Institute, but due to military infighting never used their unique fleet potential.

U.S. submarines attacked and destroyed Imperial Japanese Navy warships and merchant ships in the Pacific, according to the National Parks Service. "U.S. submarines destroyed 1,314 enemy warships in the Pacific, representing 55% of all Axis power warships lost and a total of 5.3 million tons of shipping," said Naval historian Gary E. Weir.

American success came at a great cost, 52 submarines were lost and 3,056 men were killed – the greatest number of casualties of all Armed forces in the war.

In:
• Submarine
• Titanic
• Navy

Cara Tabachnick

Cara Tabachnick is a news editor for CBSNews.com. Contact her at [email protected]