RV Petrel

The team, while onboard Octopus, mapped 380 sq mi (980 km²) of Ironbottom Sound in January 2015, identified 29 wreck locations, seven wreck debris fields, and several possible plane locations. Of the 29 wrecks located, six were positively identified and confirmed to be USS Astoria, Quincy, Vincennes, Northampton, Atlanta, and HMAS Canberra. Eleven wrecks were "tentatively" identified to be USS Walke, the Japanese destroyer Ayanami, USS De Haven, the Japanese destroyers Yūdachi, Fubuki, USS Laffey, USS Monssen, USS Barton, USS Cushing, USS Little, and USS Preston. The identification using the sonar imagery with vessel measurements and historical records is pending confirmation by ROV exploration. The remaining 12 wreck locations were not identified during the expedition and require further study.[7]

After several years of searching, the same team discovered the Japanese battleship Musashi in March 2015. This discovery made news headlines around the world.[8]

In August 2015, the team recovered the bell of HMS Hood after obtaining license from the UK Ministry of Defense. The recovery of the bell was performed upon the request of the HMS Hood Association. Only three of HMS Hood's crew survived and it was the wish of one of them to recover ship's bell as a memorial to shipmates. The bell from HMS Hood was unveiled by the Princess Royal on 24 May 2016 to mark the 75th anniversary of the Royal Navy's largest loss of life (1,415 sailors) from a single vessel.[9]

Bluefin 12 AUV mapping of seabed around Malta

While onboard Octopus, the project crew deployed a Bluefin 12D AUV and mapped 630 km² (243 sq mi) of seabed around Malta in September 2015. Sonar images of shipwrecks, several aircraft, torpedoes, and debris field were captured by the AUV.

RV Petrel has an Argus 80 kW/107HP free-flying work-class ROV with a 100 kg (220 lb) payload capability, and has these features: 750 kg horizontal thrust; station-hold facility; sonar feature-based navigation mode; various manipulator configurations from two Schilling T4s; one Schilling Orion 7P; one Rigmaster 5 function; zip pump; sticky feet; 6 in (150 mm) jaws of life; and a 38-mm Webtool with intensifier. She is tethered with an armored 17-mm-thick cable. Recently, the ROV was mounted with an R2Sonic MBES.

The Remus 6000 AUV is 28 in (711 mm) in diameter AUV, capable of speeds up to 5 knots (9 km/h; 6 mph), and has a mission duration up to 22 hours. It is rated to dive down to 6,000 m, normally flies 100 m (328 ft) above the seabed, scans 1,000 m (3,281 ft) on each side, and can map from 100 to 150 km² (39 to 58 sq mi) during each deployment. It is the only privately owned REMUS 6000 AUV in the world.

The echosounder (MBES) package aboard RV Petrel consists of one Kongsberg EM710 hull-mounted multibeam system, one Kongsberg EA600 hull-mounted singlebeam system, one ROV-mounted BlueView M450 2D multibeam imaging sonar, and one EdgeTech 2205 AUV-mounted sidescan array (75/230 kHz with interometric bathymetry). A R2Sonic MBES was recently added to Petrel's ROV.

RV Petrel's electric motors enable it to hold station over a wreck. She has four DGPS, one HiPAP 502, one HiPAP 102, two SeaPath 200, two Standard Gyro, and one fanbeam. She is classified as a Dynamic Positioning Vessel 2.

The ship has four Mitsubishi S16R-MPTK diesel engines, totaling 6,760 kW (9,065 hp) and driving four ABB AMG 500M4 auxiliary electric generators, generating 6,400 kW (8,583 hp). These, in turn, power the five thrusters - two aft fixed azimuths at 2,000 kW (2,682 hp) each, one forward retractable azimuth at 1,000 kW (1,341 hp), and two forward fixed tunnels at 1,000 kW each.

Petrel found the Italian Regia Marina World War II destroyer Artigliere in March 2017.[10]

Petrel found USS Indianapolis in August 2017.[11] One of the most elusive shipwrecks in history, Indianapolis was finally located on 19 August 2017 at a depth of 5,500 m (18,000 ft) in the Philippine Sea. The discovery became headline news around the world and introduced Petrel as Paul Allen's newest addition to his expedition fleet. Kraft said of the elusive Indianapolis, "We did 18 search grids, each one is about a 120 square kilometers and that took us the course of a couple of months. It was about 26 days of searching."[4]

The Indianapolis wreck is upright with her hull and armaments intact and well preserved in the depth. Her bow number 35 was seen by the ROV. Rusticles or oxidized wrought iron were found by the crew emerging from one of the main guns of the ship.[12]

After discovering USS Indianapolis, Petrel sailed to Surigao City in October 2017 to participate in the 73rd commemoration of the Battle of Surigao Strait.[13] In November 2017, after getting the nod from the Philippines' National Museum, Petrel surveyed Surigao Strait and discovered the wrecks of the Japanese battleships Yamashiro, Fusō, destroyers Michishio, Yamagumo, and Asagumo. Each one was investigated by the ship's ROV and an onboard local historian confirmed the identity of the wreck.[14]

In December 2017, Petrel explored Ormoc Bay and discovered the wrecks of USS Ward, USS Cooper, the Japanese destroyer Shimakaze, and what is believed to be two Yūgumo-class destroyers. The discovery of the wreck of USS Ward was a central theme for the 76th commemoration of the Attack on Pearl Harbor on 7 December.[15]

In early January 2018, Petrel returned to Ormoc Bay and dived one of the Yūgumo-class destroyers found in 2017. Based on the 127 mm (5 in) guns and armament configuration, she was identified to be Hamanami. 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. The convoy was attacked by aircraft from Task Force 38 in the Battle of Ormoc Bay. Petrel and Octopus also dove their manned submersible Pagoo on USS Cooper.

In February 2018, Petrel, with a US Navy team aboard, located and mapped the wreckage of a C-2A Greyhound aircraft that crashed into the Philippine Sea en route to USS Ronald Reagan on 22 November 2017.[16]

On 4 March 2018, Petrel explored the Coral Sea and discovered the wreck of the aircraft carrier USS Lexington, which sank during the Battle of the Coral Sea.[17]

On 17 March 2018, Petrel located the wreck of the antiaircraft light cruiser USS Juneau. 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.[18][19]

On 11 April 2018, Petrel located the wreck of the light cruiser USS Helena. Helena was sunk during the Battle of Kula Gulf in 1943 by three torpedoes fired from a Japanese destroyer with a loss of 168 of her crew.[20]

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. This exploration published on 23 April 2018, was supervised by Find AE1 Ltd in partnership with the Australian National Maritime Museum, the Royal Australian Navy, Curtin University, the Western Australian Museum, and the Submarine Institute of Australia. The approval for the survey was granted by Papua New Guinea National Museum and Art Gallery.

Petrel found the wreck of the Japanese destroyer Niizuki wreck upright in 745 m (2,444 ft) of water in January 2019. While the wreck was heavily damaged, her mast is still attached and complete. 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).[21] Niizuki's discovery is also noteworthy as the photos of the wreck are the first photos of the ship to exist; no photos of her in service are known to have been taken.

In February 2019, the Japanese cruiser Jintsū's wreckage was discovered by Petrel near the mouth of Kula Gulf in the Solomon Islands. The broken cruiser rests in 900 m (3,000 ft) of water. Her bow section is lying on its port side and the stern section is upright.[22]

On 6 February 2019, the discovery of the Japanese battleship Hiei was announced, the first Japanese battleship sunk in World War II. According to Petrel, Hiei now lies upside down in 900 m (3,000 ft) of water northwest of Savo Island in the Solomon Islands. Hiei is the fourth Japanese battleship found by Petrel's crew. The Japanese battleship Musashi was found in March 2015, and the Fusō-class battleships Fusō and Yamashiro were found in November 2017. Petrel was also able to survey another Kongō-class battlecruiser, Kirishima, in a separate mission. Lead researcher Paul Mayer said that Hiei lies 4 nautical miles (7.4 km; 4.6 mi) away from Kirishima.[23]

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.[24] She is in remarkably good condition. She sits right-side up with her island still in place. A portion of her flight deck has collapsed due to the fire that raged on her decks during the battle. A portion of her stern is torn away, but the hull remains mostly intact. Several aircraft are scattered among the wreck.

On 26 February 2019, the crew announced they had located the wreck of the destroyer USS Strong, resting at a depth of 1,000 ft (300 m).[25] She rests in pieces, the largest of which is the heavily damaged forward section of the ship laying on its port side. The rest of the ship was largely fragmented by the detonation of her depth charges and lies in a compact debris field that includes the ship's boilers, propellers, and wheelhouse.[26]

On 13 March 2019, the crew announced they had located the wreck of the aircraft carrier, USS Wasp resting at a depth of 13,800 feet (4,200 m).[27] 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. The island itself is still in place, though the funnel structure was ripped off during the sinking. Several aircraft were also found in the debris field, including Dauntlesses and Avengers.[28]

On 4 May 2019, the crew announced they had located the wreck of the Japanese heavy cruiser Furutaka at a depth of 4,600 ft (1,400 m). She lies in two sections, with the bow sitting near the main part of the wreck, which is upright and the bridge is about 2,000 ft (610 m) away.[29][30]

On 1 July 2019, it was announced that the wreck of the Japanese cruiser Maya had been found off the coast of the Philippine island of Palawan. She is mostly intact, with the exception of her forward bow, which broke off and is lying upside down just astern of the rest of the ship. Her bridge and guns are also intact. She lies in 1,850 m (6,070 ft) of water.[31]

On 9 September 2019, it was announced that the wreck of the Japanese cruiser Mogami had been found in the Bohol Sea. She lies mostly intact, with the exception of her forward bow, which has been blown off, but lying nearby. She sits straight side up at a depth of 1,450 m (4,760 ft).[32]

On 10 October 2019, it was announced that the wreck of the escort carrier, USS St. Lo, the first ship to have been sunk by a kamikaze, had been discovered on 25 May. She lies at a depth of 15,538 feet (4,736 m) on the edge of the Philippine Trench off the coast of Samar. She sits upright relatively intact, with notable battle damage. She is the first escort carrier to have been found.

On 18 October 2019, Petrel announced they had discovered the wreck of the Japanese aircraft carrier Kaga, off the coast of Midway Atoll. She lies straight side up, but with heavy battle damage, 5,400 metres (17,700 ft) below the surface. She is the first Japanese aircraft carrier to have been found.[33]

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). It is reported that the wreck is upright, on its keel and is largely intact.[34] Due to damage sustained by the ROV during recovery from the preceding survey of Kaga, and a number of other factors, Petrel was unable to conduct a photographic survey of Akagi.[35]

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. She lies upright with her bow section torn off, 5,173 metres (16,972 ft) deep.[36]

On 30 October 2019, it was announced that the wreckage of a destroyer believed to be USS Johnston was located. It is believed to be the deepest ever located shipwreck at 20,406 feet (6,220 m) deep.[37]

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. Both wrecks were found 2,200 metres (7,200 ft) apart at a depth of 500 metres (1,600 ft) in the Sibuyan Sea.[38] Both wrecks sit straight side up and are in good condition.

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 Luukai[39] north of Oahu at a depth of 4,720 m (15,490 ft). The drone had broken its tether and was lost on the ocean floor on 20 July 2019. To retrieve Luukai, the team lowered a lift elevator and Petrel's ROV worked on the recovery procedure. Luukai was recovered by the joint team on 29 August 2019.[40]

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. Through several weeks in January 2020, in the Brazil Basin of the Atlantic, Petrel and National Oceanic and Atmospheric Administration (NOAA) deployed a number of standard Navis floats (2000-m profiles), and deep SOLO floats (6000-m profiles).

As part of the Deep Argo project, a multiyear partnership between the NOAA Pacific Marine Environmental Laboratory (NOAA PMEL) and the Paul G. Allen Family Foundation, the project aimed for a final deployment of Deep Argo floats aboard Petrel. Thousands of these floats are freely drifting around the globe to measure the temperature, salinity, and turbidity of the upper ocean, at depths down to 2,000 m (6,600 ft) and deeper to 6,000 m (20,000 ft).[41] The Foundation committed $4 million to NOAA to help implement the Deep Argo effort.[42]

In June 2020, Petrel had a Kongsberg EM124 1°x2° full ocean MBES installed.  A sub-bottom profiler, a Kongsberg SBP 29 6° system, was also installed on the ship. Both were tested in the Atlantic Ocean, giving detailed bathymetry readings from 400 to 4,800 m (1,300 to 15,700 ft) depths.

On 11 June 2020, Petrel announced on its Facebook page that it was going to be moored indefinitely. The announcement read, "The impact of the COVID-19 crisis has changed the world for the long term in ways that we never could have imagined. As a result of operational challenges from the pandemic, R/V Petrel will be placed into long-term moorage and she will not be deployed for the foreseeable future. We were tasked with a monumental mission – discover, educate, and honor – and we’re hopeful we will eventually be back in service."

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. I am hopeful that Petrel will eventually be back in service, supporting the collection of ocean data and science."[43]

Petrel, after her drydock in Florida, set sail for her final destination Leith, Scotland, on 16 August 2020. She arrived in Leith on 3 September 2020. She currently remains in port.[44]