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 All data associated with this expedition have been archived and are publicly available through the NOAA Archives.

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 All data associated with this expedition have been archived and are publicly available through the NOAA Archives.

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.

From July 9-30, 2022 (Norfolk, VA to Horta, Faial, Azores) NOAA Ocean Exploration completed the Voyage to the Ridge 2 expedition (EX-22-05), a combined mapping and remotely operated vehicle (ROV) expedition to the Mid-Atlantic Ridge and Azores Plateau. Operations during this 22-days at sea expedition included the completion of 10 successful ROV exploration dives in the vicinity the Azores and the Mid-Atlantic Ridge north of the Azores. ROV dives were conducted in water depths ranging from 420 m to 3350 m for a total of almost 53 hours of bottom time. EX-22-05 also collected 49,080 square kilometers of seafloor bathymetry and associated water column data using an EM304 multibeam sonar.

From August 6 - September 2, 2022 (Horta, Faial, Azores to San Juan, Puerto Rico) NOAA Ocean Exploration completed the Voyage to the Ridge 3 expedition (EX-22-06), a combined mapping and remotely operated vehicle (ROV) expedition to the Mid-Atlantic Ridge and Azores Plateau, Mid-Atlantic Ridge, and U.S. waters in the vicinity of Puerto Rico and the U.S. Virgin Islands. Operations during this 28-day expedition included the completion of 9 successful ROV exploration dives in the vicinity of the Azores, the Mid-Atlantic Ridge south of the Azores, and Puerto Rico. ROV dives were conducted in water depths ranging from 250 m to 6000 m for a total of 41 hours of bottom time. EX-22-06 also collected 56,769 square kilometers of seafloor bathymetry and associated water column data using an EM304 multibeam sonar. All data associated with this expedition have been archived and are publicly available through the NOAA Archives.

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 Humaitá (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.

From July 9-30, 2022 (Norfolk, VA to Horta, Faial, Azores) NOAA Ocean Exploration completed the Voyage to the Ridge 2 expedition (EX-22-05), a combined mapping and remotely operated vehicle (ROV) expedition to the Mid-Atlantic Ridge and Azores Plateau. Operations during this 22-days at sea expedition included the completion of 10 successful ROV exploration dives in the vicinity the Azores and the Mid-Atlantic Ridge north of the Azores. ROV dives were conducted in water depths ranging from 420 m to 3350 m for a total of almost 53 hours of bottom time. EX-22-05 also collected 49,080 square kilometers of seafloor bathymetry and associated water column data using an EM304 multibeam sonar.

From August 6 - September 2, 2022 (Horta, Faial, Azores to San Juan, Puerto Rico) NOAA Ocean Exploration completed the Voyage to the Ridge 3 expedition (EX-22-06), a combined mapping and remotely operated vehicle (ROV) expedition to the Mid-Atlantic Ridge and Azores Plateau, Mid-Atlantic Ridge, and U.S. waters in the vicinity of Puerto Rico and the U.S. Virgin Islands. Operations during this 28-day expedition included the completion of 9 successful ROV exploration dives in the vicinity of the Azores, the Mid-Atlantic Ridge south of the Azores, and Puerto Rico. ROV dives were conducted in water depths ranging from 250 m to 6000 m for a total of 41 hours of bottom time. EX-22-06 also collected 56,769 square kilometers of seafloor bathymetry and associated water column data using an EM304 multibeam sonar. All data associated with this expedition have been archived and are publicly available through the NOAA Archives.

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 Humaitá (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.