In October 2022, she was purchased by the United States Navy's Naval Facilities Engineering Systems Command, for operation under Oceaneering International management.

[5] Prior to 2020, the primary mission of the ship, which was fully funded by Allen's estate, was to explore historically significant wrecks at challenging depths and conditions.

A precondition set by Allen was for discovered wrecks to be respected as war graves and their locations kept secret, known to only national governments and museums.

In the PBS documentary USS Indianapolis Live from the Deep, Allen said, "We've done a number of these explorations to try to find sunken warships.

Robert Kraft, who served as subsea director for Allen, and Paul Mayer, Petrel's lead researcher, traveled to Japan to hand over ROV video of Imperial Japanese Navy wrecks to the Yamato Museum.

The project crew consisted of Kraft the expedition leader, Mayer as lead researcher, four ROV pilots and technicians, one AUV specialist, one multibeam surveyor, one videographer, and one systems support engineer.

[10] While on board Octopus, the project crew deployed a Bluefin 12D AUV and mapped 630 km2 (243 sq mi) of seabed around Malta in September 2015.

Following the Musashi discovery and the Hood expedition in 2015, Allen bought Petrel in 2016, refitting her as a dedicated research and exploration platform.

[14] In November 2017, after gaining approval from the Philippines' National Museum, Petrel surveyed Surigao Strait and discovered the wrecks of the Japanese battleships Yamashiro, Fusō, and the destroyers Michishio, Yamagumo, and Asagumo.

The identification also validated the final resting places of the other ships of the lost Japanese convoy TA-4: the destroyers Shimakaze, Wakatsuki and Naganami.

In February 2018, Petrel, with a US Navy team aboard, located and mapped the wreckage of a Grumman C-2 Greyhound aircraft that crashed into the Philippine Sea en route to USS Ronald Reagan on 22 November 2017.

Juneau was sunk by the Japanese submarine I-26 in the aftermath of the first Naval Battle of Guadalcanal, sinking with the loss of 687 men, which included the five Sullivan brothers.

[21] The Royal Australian Navy's submarine HMAS AE1, which was lost at sea with all hands on 14 September 1914, and only discovered in December 2017 on the seafloor off the Duke of York Islands in Papua New Guinea (PNG), was visited by Petrel's ROV.

Petrel's crew devised a close-up camera to view details inside the torpedo tube and engine telegraph.

The find of Niizuki was noteworthy because she was credited for sinking USS Strong with the longest torpedo shot ever, with estimates ranging from 7 to 11 nautical miles (13 to 20 km; 8.1 to 12.7 mi).

In February 2019, the Japanese cruiser Jintsū's wreckage was discovered by Petrel near the mouth of Kula Gulf in the Solomon Islands.

[24] On 12 February 2019, the crew announced they had located the wreck of the aircraft carrier USS Hornet at a depth of more than 17,700 ft (5,400 m) off the Solomon Islands.

[28] The ship sits upright, though appears to have broken in two places, just forward and just aft of the island, apparently on impact with the seabed.

On 18 October 2019, Petrel announced they had discovered the wreck of the Japanese aircraft carrier Kaga, off the coast of Midway Atoll.

[34] On 20 October 2019, the director of undersea operations Rob Kraft and Naval History and Heritage Command historian Frank Thompson aboard Petrel identified the wreck of the Japanese aircraft carrier Akagi using high-frequency sonar.

Located 1,300 miles (2,100 km) north west of Pearl Harbor, Hawaii, Akagi was found at a depth of 18,011 feet (5,490 m).

[36] On 26 October 2019, the search team announced they had discovered, on 5 May earlier in the year, the wreck of the Japanese cruiser Chōkai on the edge of the Philippine Deep.

[38] Her identity was confirmed on 31 March 2021, when the submersible DSV Limiting Factor of Caladan Oceanic surveyed and photographed the deeper main wreck.

[41] On 19 December 2019, it was announced that Petrel had located and surveyed the wrecks of the Philippine ferry, MV Doña Paz and the oil tanker MT Vector.

On 24 December 2019, news came out that Petrel and a team from University of Hawaii School of Ocean and Earth Sciences and Technology (UH-SOEST) located and successfully recovered the latter's lost ROV named Luu'kai[43] north of Oahu at a depth of 4,720 m (15,490 ft).

[44] After finding Kaga and Akagi, Petrel crossed the Pacific in the fourth quarter of 2019 and stationed in the Atlantic Ocean to launch Deep Argo floats beginning January 2020.

Robert Kraft, subsea director, said, "I am proud of the successful Petrel missions that have brought information and closure to so many families and friends of WWII heroes.

[48] In October 2022, Petrel was purchased by the United States Navy for its Naval Facilities Engineering and Expeditionary Warfare Center (NAVFAC EXWC), to be operated by the American company Oceaneering International.

[49] On 22 March 2023, whilst dry-docked at Imperial Dock in Leith, Edinburgh, the vessel became dislodged from her holdings in strong winds and toppled over to an angle of 45 degrees.