The wreck of a legendary WWII US submarine has been found at the bottom of the South China Sea

US NHHC confirmed the find on Thursday, crediting data collected by Lost 52, a project dedicated to finding and memorializing all 52 US submarines sunk during the war.

Lost 52 is headed by entrepreneur and ocean explorer Tim Taylor, along with diving entrepreneur Christine Dennison.

They used advanced photogrammetry and underwater robotics to locate and take stunning images of the Harder, which was sunk by Japan off the coast of the Philippines in 1944.

Lost submarines are notoriously difficult to locate and identify, as Business Insider’s Elias Chavez previously reported.

“Submarines by their very design can be a challenge to identify, but the excellent state of preservation of the site and the quality of the data collected by Lost 52 allowed for NHHC to confirm the identity of the wreck as Harder,” the NHHC said in a statement.

The Harder — sailing under the slogan “Hit ’em Harder” — was sunk on August 24, 1944, after racking up a prodigious number of kills.

Seventy-nine servicemen were aboard, including the famed Commander Samuel Dealey.

“Harder was lost in the course of victory,” NHHC Director and retired Rear-Admiral Samuel J. Cox said, adding that the sub used “particularly audacious attacks” against the Japanese.

In the course of a single patrol, Harder sank three enemy destroyers, as well as destroying or damaging a further two, according to NHHC.

The Harder’s final patrol saw it seek out new targets alongside the USS Hake near Dasol Bay in the northern Philippines.

The pair started to hunt two Japanese ships. Harder fired three torpedoes before it fell victim to a series of depth charges. The Hake took evasive maneuvers, but the Harder was not so lucky.

The Lost 52 team has previously located at least six other US submarines.

“We maintain a policy of not disclosing current ongoing expedition plans” out of respect for families, the group says on its website, adding that it only announces discoveries once they are fully confirmed.

Lost 52’s cofounder Taylor is the CEO of Tiburon Subsea, which focuses on ocean-floor data collection using underwater drones.

The discovery — which Taylor told BI is part of a multi-year $50 million project — illustrates the growing use of underwater photogrammetry to illuminate deep-sea sites that are otherwise difficult to reach.

Finding the Harder “highlighted the importance of ocean data collection and the significance of underwater robotic technology,” Taylor told BI.

It’s part of a growing “blue economy” that is predicted to be a $30 trillion industry by 2030, he added.

Undersea photogrammetry uses divers or remotely operated vehicles to take thousands of pictures from all sides, which are then stitched together using software, according to the National Oceanic and Atmospheric Administration.