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Okeanos Explorer

The following pages provide information about the Okeanos Explorer expeditions conducted, and enables direct access to corresponding data and products.

Galapagos Rift Expedition - EX1103L2

In June and July 2011, the GALREX 2011 expedition explored the diverse habitats and geologic settings of the deep Galapagos region, including axial volcanic ridges, hydrothermal vents, off-axis sulfide mounds, and seamounts. The discovery of deep-sea hydrothermal vents and associated organisms on the Galapagos Rift (GR) in 1977 profoundly changed our view of the deep-sea and revolutionized the biological and Earth sciences. During the 2011 field season, the NOAA Ship Okeanos Explorer provided scientists, engineers, and the public with an opportunity to explore unseen areas and revisit historical sites in the GR. More than 40,000km2 of seafloor were mapped by the ship's multibeam sonar, 11 CTD tows completed a ~400 km-long hydrothermal plume survey of the unexplored eastern arm of the Rift, and 12 ROV dives collected more than 90 hours of high-definition digital video. Data and ROV video feeds were transmitted by broadband satellite from the ship to a team of scientists onshore. The expedition team evaluated seafloor observations, directed seafloor ROV, CTD, and mapping operations in real-time, and maintained a portal for outreach.

Mid-Cayman Rise Expedition - EX1104

During August 2011, a team of scientists and technicians both at-sea and on shore conducted exploratory interdisciplinary investigations on the geology, marine life, and hydrothermal systems at the Mid-Cayman Rise.

The 17-day expedition included 10 days of operations at the Mid-Cayman Rise and one day at the Cayman Trough Fracture Zone, southwest of the Cayman Islands and located entirely within their Exclusive Economic Zone.

Gulf of Mexico Exploration - EX1202L2

From March to April 2012, NOAA Ship Okeanos Explorer conducted exploratory investigations on the diversity and distribution of deep-sea habitats and marine life in the northern Gulf of Mexico.

Gulf of Mexico Exploration - EX1202L3

From March to April 2012, NOAA Ship Okeanos Explorer conducted exploratory investigations on the diversity and distribution of deep-sea habitats and marine life in the northern Gulf of Mexico. During Leg 3, cold seeps, deep coral communities, undersea canyons, shipwrecks, brine pools, and mud volcanoes were explored.

Northeast U.S. Canyons Exploration - EX1304L1

The first leg of the 2013 Northeast U.S. Canyons Expedition explored diverse habitats and geological settings of the deep canyons region off the Northeast United States. The remotely operated vehicle Deep Discoverer (ROV D2) completed 16 dives to depths ranging from 500 to 2,200 meters. D2 surveyed four major submarine canyons, including Block, Alvin, Atlantis, and Hydrographer; one unnamed minor canyon; three priority sites considered to be geohazard areas; and three potential (and confirmed) hydrocarbon seep areas.

Northeast U.S. Canyons Exploration - EX1304L2

During Leg 2 of this expedition, ROV Deep Discoverer (D2) completed fifteen dives, ranging in depth from 490 to 3300 m at five named canyons (Nygren, Heezen, Oceanographer, Lydonia, and Welker), one minor canyon (unnamed near Shallop Canyon), two intercanyon sites, two USGS geohazards targets, and Mytilus Seamount. Many of the ROV dives were the first exploration and visual examination of this region.

Gulf of Mexico - EX1402L3

Okeanos Explorer EX1402 Leg 3 - the final voyage in the series of three ocean exploration cruises as part of the 2014 Gulf of Mexico Expedition conducted 16 highly successful telepresence-enabled remotely operated vehicle (ROV) dives in two different areas of the Gulf:

1. The northwestern part of the basin, characterized by a very thick (~12-14 kilometer) accumulation of sediments mobilized from below by evaporites/salt, and

2. The central part of the Florida Escarpment, the western edge of a thick carbonate platform, and the outer shelf next to it.

Atlantic Canyons and Seamounts - EX1404L2

From September 4 - September 10, NOAA Ship Okeanos Explorer deployed the Deep Discoverer and Seirios on three dives in the Canyons along the continental shelf. These canyons proved to be biodiversity hotspots.

Atlantic Canyons and Seamounts - EX1404L3

From September 16 - October 7, NOAA Ship Okeanos Explorer deployed the Deep Discoverer and Seirios camera sled on thirteen dives in the Canyons and the New England Seamount Chain. Highlights from these dives include observations of deep sea predation, a series of caves inhabited by octopuses, dragonfish, and several areas of high coral density.

Caribbean Sea, Puerto Rico Trench - EX1502L3

During Leg 3, the at-sea and shore-based science teams worked together to investigate unknown and poorly known areas, including the Puerto Rico Trench, Muertos Trough, Mona Passage, and the Virgin Islands Trough.

Campaign to Address Pacific monument Science, Technology, and Ocean NEeds (CAPSTONE) NWHI Exploration Leg II - EX1504L2

Operations for Leg 2 focused on areas around the North West Hawaiian Islands. Dives took place in deep-waters offshore of Oahu, Ni'ihau and in and just outside of Papahanaumokuakea Marine National Monument (PMNM).

CAPSTONE Leg III: Main Hawaiian Islands and Geologists Seamounts (ROV/Mapping) - EX1504L3

Operations for the third leg of the 2015 Hohonu Moana Expedition included ROV, mapping, CTD rosette and telepresence-based remote participation.

Campaign to Address Pacific monument Science, Technology, and Ocean NEeds (CAPSTONE) Leg IV - EX1504L4

Leg 4 consisted of a telepresence-enabled ROV cruise which focused on the offshore Johnston Atoll.

Exploring the Deep Waters off Hawaii - EX1603

Operations included collecting baseline-characterization data of poorly known areas over a wide area of the US EEZ around the Hawaiian Island Chain, focusing primarily in and around Papahanaumokuakea Marine National Monument (PMNM).

CAPSTONE CNMI & Mariana Trench MNM (ROV & Mapping) - EX1605L1

Telepresence-enabled ROV/CTD/mapping cruise focused on the southern half of the CNMI and the MTMNM.

CAPSTONE CNMI & Mariana Trench MNM (ROV & Mapping) - EX1605L3

Telepresence-enabled ROV/CTD/mapping cruise focused on the northern part of the CNMI and the MTMNM.

CAPSTONE Wake Island Unit PRIMNM (ROV & Mapping) - EX1606

This expedition addressed science themes, priority areas, and exploration targets put forward by scientists and managers across the broad ocean science community.

FY17 Ship and ROV Shakedown - EX1608

Operations used the ship's deep water mapping systems (Kongsberg EM302 multibeam sonar, EK60 splitbeam fisheries sonars, ADCPs, and Knudsen 3260 chirp sub-bottom profiler sonar), NOAA's two-body 6000 m remotely operated vehicles (ROVs Deep Discoverer and Seirios, and the ship's high-bandwidth satellite connection for real-time ship to shore communications.

American Samoa Expedition: Suesuega o le Moana o Amerika Samoa (ROV/Mapping) - EX1702

Operations for this cruise were conducted 24 hours/day and consisted of daily remotely operated vehicle (ROV), overnight mapping, CTD casts and full shore-based participation via telepresence. Operations were conducted within several marine protected areas. Operations were planned in the Rose Atoll Marine National Monument, National Marine Sanctuary of American Samoa, offshore (not within) of the National Park of American Samoa, and the waters of both American Samoa and Samoa.

Howland/Baker PRIMNM and PIPA (ROV/Mapping) - EX1703

EX-17-03 operations were conducted 24 hours/day and consisted of daily remotely operated vehicle (ROV), overnight mapping, CTD casts and full shore-based participation via telepresence. Operations were conducted within several marine protected areas. The expedition commenced on March 7th, 2017 in Apia, Samoa and concluded on March 29, 2017 in Apia, Samoa.

American Samoa, Kingman/Palmyra, Jarvis (ROV & Mapping) - EX1705

EX-17-05 operations occurred in the waters of American Samoa, the Cook Islands, Kiribati, the high seas and the US EEZ around Jarvis Island, Kingman Reef, and Palmyra Atoll. This cruise collected baseline data and information to support priority NOAA science and management needs including in multiple marine protected areas of the Pacific Ocean.

Johnston Atoll (ROV/Mapping) - EX1706

Operations included the use of the ship's deep water mapping systems (Kongsberg EM302 multibeam sonar, EK60 split-beam fisheries sonars, Knudsen 3260 chirp sub-bottom profiler sonar, and Teledyne Acoustic Doppler Current Profilers), XBT and Underway CTD casts in support of multibeam sonar mapping operations, OER's 6000 m two-body ROV Deep Discoverer and Seirios, and the ship's high-bandwidth satellite connection for continuous real-time ship-to-shore communications.

Musicians Seamounts (ROV & Mapping) - EX1708

Operations for this cruise were conducted 24 hours/day and consisted of daily remotely operated vehicle (ROV), overnight mapping, and full shore-based participation via telepresence. Operations included the use of the ship's deep water mapping systems (Kongsberg EM302 multibeam sonar, EK60 split-beam fisheries sonars, Knudsen 3260 chirp sub-bottom profiler sonar, and Teledyne Acoustic Doppler Current Profilers), XBT and CTD casts in support of multibeam sonar mapping operations, OER's two-body ROV Deep Discoverer and Seirios, and the ship's high-bandwidth satellite connection for continuous real-time ship-to-shore communications. Operations were planned in and around Hawaii, the US EEZ, and in the High Seas around the Musicians Seamounts.

Gulf of Mexico (ROV and Mapping) - EX1711

Operations included the use of the ship's deep water mapping systems (Kongsberg EM302 multibeam sonar, EK60 split-beam fisheries sonars, Knudsen 3260 chirp sub-bottom profiler sonar, and Teledyne Acoustic Doppler Current Profiler), XBT and CTD casts in support of multibeam sonar mapping operations, OER's two-body ROV Deep Discoverer and Seirios, and the ship's high-bandwidth satellite connection for continuous real-time ship-to-shore communications.

Gulf of Mexico (ROV and Mapping) - EX1803

Operations included the use of the ship's deep water mapping systems (Kongsberg EM302 multibeam sonar, EK60 split-beam fisheries sonars, Knudsen 3260 chirp sub-bottom profiler sonar, and Teledyne Acoustic Doppler Current Profiler), XBT and CTD casts in support of multibeam sonar mapping operations, OER's two-body ROV Deep Discoverer and Seirios, and the ship's high-bandwidth satellite connection for continuous real-time ship-to-shore communications. Operations are planned in and around the US Gulf of Mexico and potentially the international waters of the Gulf.

Mid and Southeast US (ROV and Mapping) - EX1806

Operations included the use of the ship's deep water mapping systems (Kongsberg EM302 multibeam sonar, EK60 split-beam fisheries sonars, Knudsen 3260 chirp sub-bottom profiler sonar, and Teledyne Acoustic Doppler Current Profiler), XBTs in support of multibeam sonar mapping operations, CTD casts, OER's two-body ROV Deep Discoverer and Seirios, and the ship's high-bandwidth satellite connection for continuous real-time ship-to-shore communications. Operations are planned throughout the South Atlantic Bight, offshore Florida, Georgia, South Carolina, North Carolina, and Virginia.

Puerto Rico and U.S. Virgin Islands (ROV & Mapping) - EX1811

Operations included the use of the ship's deep-water mapping systems (Kongsberg EM302 multibeam sonar, EK60 split-beam fisheries sonars, Knudsen 3260 chirp sub-bottom profiler sonar, and Teledyne Acoustic Doppler Current Profiler), XBTs in support of multibeam sonar mapping operations, CTD casts, OER's two-body ROV system (Deep Discoverer and Seirios), and the ship's high-bandwidth satellite connection for continuous ship-to-shore communications. Operations focused on exploring deep waters (>250 m) in the U.S. exclusive economic zone (EEZ) of the Caribbean Sea, as well as in territorial waters surrounding surrounding Puerto Rico and the U.S. Virgin Islands.

2019 Field Season Shakedown - EX1902

This shakedown mission, which began in Pascagoula, Mississippi on May 12, 2019 and concluded on May 24, 2019 in Key West, Florida, came after the winter scheduled drydock and dockside shipyard repair period. While underway, 24-hour operations focused on preparing deep-sea mapping and water column sonars and remotely operated vehicle (ROV) systems for the remainder of 2019 expeditions. Three "engineering dives" were conducted during the first part of the expedition. The dives allowed members of the Global Foundation for Ocean Exploration to calibrate the ROV's ultra short baseline (USBL) positioning system, test a new suction sampling device, test on-ship data transfer and telepresence systems, and train new team members. As the dives focused on testing new equipment, no physical samples were collected for later analyses. During the third ROV dive on May 16, while conducting an "engineering dive" to test new remotely operated vehicle (ROV) equipment, the team made an unexpected - and exciting - discovery: the wreck of what is likely a mid-19th century wooden sailing vessel. Mapping shakedown operations during the expedition included calibrating the ship's EM302 multibeam sonar (used to map the seafloor and water column) and the EK60 split-beam sonar (used to explore the water column), integrating and calibrating a new Simrad EK80 split-beam sonar (for further water column exploration), and installing and testing a new sonar synchronization unit (K-Sync - to reduce potential interference between different sonars).

SE US Atlantic Cont Margin Mapping - EX1903L1

During EX1903L1 5342 linear kilometers and 21,724 square kilometers of EM302 data were collected. In addition to bathymetry, these numbers also include multibeam backscatter and multibeam water column data. EX-19-03 Leg 1 operations commenced on May 30th, 2019 in Key West, Florida and concluded on June 14, 2019 in Cape Canaveral, Florida. Operations included a combination of acoustic seabed, water column, and sub-seafloor mapping and one conductivity temperature depth (CTD) cast. Operations focused in the South Atlantic Bight, off the coasts of Florida, Georgia and South Carolina all within the U.S. EEZ. Priority areas were defined with input from the OER ASPIRE 2019 workshop, Bureau of Ocean Energy Management, NOAA Southeast Deep Sea Coral Initiative, NOAA Office of Coast Survey, Seabed 2030 efforts, and the South Atlantic Fisheries Management Council. Strategic mapping objectives included subbottom data collection over key features, multibeam data collection over priority areas requiring coverage development, and multibeam holiday lines completing previous coverage on the Blake Plateau. Mapping objectives also focused on priority areas in order to optimize Remotely Operated Vehicle Dives planned for EX-19-03-Leg02 that followed this cruise.

Mid and Southeast US ROV and Mapping - EX1903L2

The deepwater areas offshore Florida, Georgia, South Carolina, and North Carolina are some of the least explored areas along the U.S. East Coast. In 2019, NOAA and partners conducted a two-part expedition to map and characterize this area to support priorities put forward by the deep-ocean science and resource management communities. The primary objective of the expedition was to survey deepwater areas offshore of Florida, Georgia, South Carolina and North Carolina in order to provide baseline information to support management and science needs. This two-part expedition used the ship's deepwater mapping systems (Kongsberg EM302 multibeam sonar, Simrad EK60 and EK80 split-beam fisheries sonars, Knudsen 3260 chirp sub-bottom profiler sonar, and Teledyne Acoustic Doppler Current Profiler [ADCP]), NOAA's two-body deepwater remotely operated vehicle (ROV), and a high-bandwidth satellite connection for real-time ship to shore communications. This cruise report details activities associated with the second leg of the Windows to the Deep 2019 expedition (EX1903L2). 19 ROV dives were conducted, ranging in depth from 298 to 3,490 meters (978-11,450 feet) to improve knowledge of unexplored areas within the U.S. Exclusive Economic Zone (EEZ) to inform management needs for sensitive habitats, maritime heritage sites, and potential resources. EX1903L2 also mapped 14,314 square kilometers of seafloor to extend bathymetric mapping coverage in the U.S.EEZ in support of Seabed 2030 and NOAA's goal to map and characterize the U.S. EEZ. Data from this expedition will help to improve our understanding of the deep-ocean habitats of the U.S. continental margin and of the connections between communities throughout the Atlantic Basin.

2019 Technology Demonstrations - EX1904

EX-19-04 mapped 7,001 square kilometers of seafloor on and off the continental shelf offshore of Virginia, Maryland, Delaware, New Jersey, New York, Rhode Island and Massachusetts during the 14 days-at-sea.

New England and Canada Mapping - EX1905L1

EX-19-05 Leg 1 collected 18,734 square kilometers (5462 square nautical miles) and 4798 linear kilometers of bathymetry and associated water column data; 37 square kilometers of this area were mapped within the U.S. Exclusive Economic Zone in depths greater than 200 meters. EX-19-05-Leg 1 departed from North Kingstown, Rhode Island on August 6, 2019 and arrived in Halifax, Nova Scotia, Canada on August 20, 2019, for a total of 15 days-at-sea. EX-19-05 Leg 1 operations involved a transit northward, crossing the continental shelf followed by focused ocean mapping operations mostly in deep (> 200 m) Canadian waters off the east coast of Nova Scotia. The cruise conducted 24 hour/day exploratory mapping operations to provide initial characterization of the region, as well as to provide data to support more in-depth exploration with remotely operated vehicles (ROVs) planned for the follow-on EX-19-05 Leg 2 expedition.

New England and Canada - EX1905L2

Using OER's dual-body ROV, the expedition completed 12 successful dives ranging in depth from 306 to 2,668 meters that explored a wide diversity of habitats and geological features, including deep-sea coral and sponge communities, deep-sea fish habitats, midwater habitats, submarine canyons, seamounts, and more. Midwater explorations at depths ranging from 700 to 2,175 meters were conducted during one ROV dive in order to investigate the diversity and abundance of the largely unknown pelagic fauna of the region. Overall, hundreds of different species were observed during ROV dive operations, including several potentially undescribed species and several range extensions. Throughout the expedition, 124 biological samples were collected (35 primary and 89 associated taxa), 26 of which likely represent either range expansions or potential new species. The remainder of the biological samples were collected to support studies on connectivity and biogeographic patterns across the Atlantic Ocean. Six high-density communities of deep-sea corals and sponges were documented during the expedition, including a high-density forest of bamboo corals at depths of 1,100 meters inside Gully Canyon, and a highly diverse and dense assemblage of deep-sea sponges and corals at depths of 2,500-2,650 meters on Retriever Seamount, which is among the deepest known such communities in the region. Additional patches of high-density communities of deep-sea corals and sponges were documented during dives on an unnamed canyon, Kinlan Canyon, Bear Seamount, and Veatch Canyon. Other noteworthy ROV observations included records of three large (> 1 meter) individuals of the endangered Atlantic Halibut, Hippoglossus hippoglossus.Additionally, ROV dives documented various unique geological features, including inactive fluid expulsion features inside Verrill Canyon, evidence of recent sediment transport within Oceanographer Canyon, and a continuous sequence of carbonate rock (>100 meters thick) with near vertical relief at Veatch Canyon. Five geological samples were collected to support laboratory analyses that will increase our understanding of the geological context of this region.

Southeastern US - EX1906

EX-19-06 collected 20,289 square kilometers (5,915 square nautical miles) and 7,594 linear kilometers of bathymetry and associated water column data. 18,110 square kilometers of this area was mapped within the U.S. Exclusive Economic Zone in depths deeper than 200m. The ship started the cruise from North Kingstown, RI on October 5, 2019 and ended in Miami, Florida on October 26, 2019. EX-19-06 operations involved a transit southward along the edge of the continental shelf followed by focused ocean mapping operations mostly in deep (>200 m) U.S. federal waters off the southeast U.S. Coast on the Blake Plateau. Some limited surveying was also completed along the U.S./Bahamas maritime boundary region. The cruise conducted 24 hour/day exploratory mapping operations to provide initial characterization of the region, as well as to provide data to support more in-depth exploration with remotely operated vehicles (ROVs) planned for the follow-on EX-19-07 expedition.

Southeastern US Deep Sea Exploration - EX1907

From October 31 to November 20, 2019 the NOAA Office of Ocean Exploration and Research (OER) conducted the 2019 Southeastern U.S. Deep-sea Exploration remotely operated vehicle (ROV) and mapping cruise (EX1907) from Miami, Florida, to Key West, Florida. Twelve ROV dives were completed, and over 12,700 square kilometers were mapped during this expedition. ROV dive operations supported the expedition objectives, including characterizing bottom fish and precious coral habitats, deep-sea coral habitats, seamounts, and fracture zones. During each dive, the ROVs descended to the seafloor and then moved from waypoint to waypoint, documenting the geology and biology of the area. Onboard and shore-based scientists identified encountered organisms to the lowest taxon possible based on data available during real-time assessment.

EM 304 Sea Acceptance Trials - EX2000

EX-20-00 departed from Pascagoula, Mississippi on March 3 and arrived in Key West, Florida on March 8, 2020. The primary purpose of this cruise was to perform the sea acceptance trials of the newly installed EM 304 topside unit. The multibeam receive array was replaced in 2018, and the transmit array is the original from the 2007 install. Visiting Kongsberg technicians performed and observed required tests to ensure acceptable functionality of the unit. These tests included a geometric calibration (patch test), speed-noise testing, and accuracy testing with both a shallow and deep reference survey.

Mapping Shakedown 2021 - EX2101

Between April 14 and May 10, 2021 EX-21-01 performed the sea acceptance testing of the newly installed Kongsberg EM 304 MKII transmit array, conducted mission readiness of the mapping systems through annual testing and calibration, and mapped unexplored areas of the Blake Plateau. In addition to the EM 304 multibeam sonar objectives, EK60/80 split-beam echosounder objectives included acceptance of the newly installed EK80 38 kHz transducer and calibration of each frequency (18, 38, 70, 120, 200 kHz). Other mission readiness objectives included ensuring functionality of all ancillary equipment, including sound speed profiling equipment, updating and refining procedural documents, and defining new procedures for supporting shore-based processing using the Cloud. EX-21-01 collected 22,187 square kilometers of bathymetry and associated water column data, with 18,773 square kilometers being within the U.S. Exclusive Economic Zone and Territorial Sea deeper than 200 m.

Technology Demonstration 2021 - EX2102

From May 14-27, 2021, NOAA Ocean Exploration led the 2021 Technology Demonstration on NOAA Ship Okeanos Explorer from Cape Canaveral, Florida, to Norfolk, Virginia. The expedition brought together NOAA's Northwest Fisheries Science Center, NASA's Jet Propulsion Laboratory (NASA JPL), the Woods Hole Oceanographic Institution (WHOI), and the Inner Space Center/University of Rhode Island (ISC/URO) to advance new ocean technologies and sampling techniques. The expedition had three overall objectives; field testing and engineering readiness of WHOI/NASA JPL Orpheus autonomous underwater vehicles, piloting environmental DNA (eDNA) collection for NOAA Ocean Exploration and mapping priority deepwater areas offshore the U.S. Southeast, largely focused on the Blake Plateau. During 14 days at sea, 8 AUV deployments were completed between 12 and 866 meters in depth. Over 724 GB of downlooking AUV 4K video were collected. The AUVs surveyed 30 linear kilometers of seafloor and logged over 16 hours of bottom time. The AUVs spent a total of 32 hours 59 minutes in the water, which included autonomous water column exploration. Twelve CTD rosette casts were completed, most simultaneous with AUV operations. Using the Niskin bottles on the CTD rosette, 120 water samples were collected for post-cruise eDNA analysis. Exploration mapping operations included acoustic data collection using the EM 304 MKII multibeam echosounder, Simrad EK60/80 split-beam echosounders, Knudsen sub-bottom profiler and Acoustic Doppler Profilers. 8,703 square kilometers of largely unmapped seafloor were mapped using the EM 304 with 8,519 square kilometers being within the U.S. Exclusive Economic Zone and Territorial Sea deeper than 200 m. All operations and data collected were in U.S. waters.

Windows to the Deep 2021 - EX2103

This Remotely Operated Vehicle (ROV) shakedown expedition aboard NOAA Ship Okeanos Explorer began in Norfolk, Virginia on June 13, 2021 and concluded on June 28, 2021 in Newport, Rhode Island. This was the first time the ROVs Deep Discoverer and Seirios were mobilized and used for ROV dives since the extensive 2021 winter dry dock repair period. While underway, 24-hour operations focused on preparing remotely operated vehicle (ROV) systems for the remainder of 2021 expeditions. Extensive testing, calibration, and troubleshooting was completed for new ROV motors, motor controllers, cameras, lighting, hydraulic systems, and a navigational sonar during 11 ROV dives. The first five dives progressively got to deeper depths ranging from 670 m to 4370 m with the primary objective of new equipment integration and personnel training. The following five dives were conducted on Caryn Seamount, and the mid-Atlantic canyons Toms, Hudson (twice), and Uchupi. The last dive of the expedition was on a recently discovered sonar anomaly that turned out to be a World War II era submarine, the Humaita (ex-USS Muskallunge). Five biological and three geological samples were collected for later analyses from Caryn Seamount and the mid-Atlantic canyons. Mapping operations during the expedition included continued calibrating and troubleshooting of the ship's new EM304 multibeam sonar and transducer array. Additional mapping operations included improving multibeam bathymetry in previously mapped areas, sub-bottom sonar surveys conducted on the Currituck landslide feature off of North Carolina, EK60 water column sonar survey of the diurnal migration above Hudson Canyon, and searching for underwater cultural heritage sites by observing sonar depth and backscatter anomalies.

North Atlantic Stepping Stones 2021 - EX2104

The 2021 North Atlantic Stepping Stones: New England and Corner Rise Seamounts expedition (EX-21-04) was a combined mapping and remotely operated vehicle (ROV) expedition to the seamounts of the Northwest Atlantic that took place between June 30 and July 29, 2021. Operations during this 30-day at sea expedition included a combination of ROV dives in support of NOAA Ocean Exploration and its partner priorities as well as exploratory mapping operations targeting areas containing no or poor quality modern mapping data. The initial focus was on the U.S. Northeast Seamount and high seas areas, however, during the expedition weather altered the planned transect to outside Bermudan waters where three dives took place before rejoining the planned dive sites exploring a total of 19 seamounts and one canyon (Hydrographer) for water column exploration. During the expedition, 20 Deep Discoverer ROV dives were conducted from 300 m to 4187 m water depth for a total of 154 hours of bottom time, and surveyed using EM 304 multibeam sonar 54,710 square km over 30 days at sea. All data associated with this expedition have been archived and are publicly available through the NOAA Archives.

U.S. Blake Plateau Mapping 1 2021 - EX2105

From August 15- September 2, 2021, NOAA Ocean Exploration conducted mapping operations on the Blake Plateau within U.S. waters, aiding in closing the gaps within this region. This cruise consisted of a strategic transit from Newport, Rhode Island to the primary working grounds off of the U.S Southeast, aimed at collecting data over previously mapped and potentially new seeps along the edge of the continental shelf. EX-21-05 collected 13,054 square kilometers of bathymetry and associated water column data, 12,989 square kilometers of which were within the U.S. Exclusive Economic Zone and Territorial Sea deeper than 200 m. The cruise concluded in Port Canaveral, FL on September 2, 2021. The exploratory mapping operations conducted during this cruise will provide initial characterization of the region, as well as data to support further exploration with remotely operated vehicles planned for EX-21-07.

U.S. Blake Plateau Mapping 2 2021 - EX2106

From September 5 - September 28, 2021, NOAA Ocean Exploration conducted mapping operations on the Blake Plateau within U.S. waters, aiding in closing the gaps within this region. The second of two cruises focused on mapping this region, EX-21-06 collected 25,800 square kilometers of bathymetry and associated water column data, 25,790 square kilometers of which were within the U.S. Exclusive Economic Zone and Territorial Sea deeper than 200 m. The exploratory mapping operations conducted during this cruise will provide initial characterization of the region, as well as data to support further exploration with remotely operated vehicles planned for EX-21-07.