At Sea With the ROVs
Dive operations during the 2026 ROV Shakedown expedition focused on the readiness of the ROVs and the ROV Team. Following calibration of the USBL (ultra-short baseline) system, which is used to determine the position of the ROVs when they’re in the water, the ROVs were ready to dive.
Remotely operated vehicle (ROV) Deep Discoverer being launched. After a year on shore, the ROVs were launched at sea for the first dive of the 2026 ROV Shakedown expedition off the southwestern coast of Oʻahu, Hawaiʻi. Unfortunately, an issue arose with Deep Discoverer, and they were recovered early to investigate. Image courtesy of NOAA Ocean Exploration, 2026 ROV Shakedown. Download largest version (jpg, 2.94 MB).
Illuminated by its companion vehicle, remotely operated vehicle (ROV) Seirios, ROV Deep Discoverer shines its own lights on the seafloor while exploring Dutton Seamount during the 2026 ROV Shakedown in the deep waters around the main Hawaiian Islands. Image courtesy of NOAA Ocean Exploration, 2026 ROV Shakedown. Download largest version (jpg, 1.83 MB).
The first dive site was relatively shallow (almost 500 meters/1,640 feet) with a largely flat sandy bottom. It provided an ideal location for testing the ROVs after so much time off line. Confident with the performance of the ROVs, the team took the vehicles into deeper water (1,400 meters/4,596 feet) for the second dive. On the final day of the expedition, they achieved the deepest depth of the expedition — 4,800 meters (almost 3 miles).
Pilot training in the control room on NOAA Ship Okeanos Explorer. Throughout the 2026 ROV Shakedown expedition, remotely operated vehicle (ROV) pilots from the NOAA Ocean Exploration Cooperative Institute trained in both the pilot (ROV Deep Discoverer) and co-pilot (ROV Seirios) positions. Here, Levi Unema (left) trains Sarah Haberstroh as pilot (middle) and Jenna Ehnot (right) as co-pilot during a dive off the southwestern coast of Oʻahu, Hawaiʻi. Image courtesy of NOAA Ocean Exploration, 2026 ROV Shakedown. Download largest version (jpg, 427 KB).
In total, six dives, which varied in depth as well as terrain, enabled the team to accomplish multiple engineering and training objectives. In addition, a new transect camera installed on Deep Discoverer was tested for its ability to enable better habitat characterization. While a push core was also set up on Deep Discoverer to expand sampling capabilities, it wasn’t tested during a dive, and a final location for the tool on the ROV had yet to be established.
Geological and Biological Highlights
Pillow lava from a past eruption of Mauna Loa seen off the coast of Kona, Hawai‘i, during the 2026 ROV Shakedown expedition. Image courtesy of NOAA Ocean Exploration, 2026 ROV Shakedown. Download largest version (jpg, 858 KB).
Remotely operated vehicle pilot practicing picking up a rock from the seafloor on Dutton Seamount during the 2026 ROV Shakedown expedition. Image courtesy of NOAA Ocean Exploration, 2026 ROV Shakedown. Download largest version (jpg, 1.57 MB).
While science operations were not a focus of this expedition, geology and biology both played an important role in ROV testing and training. The varied terrain and geology — which included flat sandy seafloors and the steep slopes of the island of Hawaiʻi and Dutton seamount — provided rich training grounds for navigation, imaging, and sample collection. And, although limited, the biology offered similar opportunities, and kept viewers of the livestream engaged.
Animals from all the major phyla were observed and included corals, anemones, jellyfish, sea stars, brittle stars, sea cucumbers, crinoids, sponges, squat lobsters, shrimp, snails, worms, and fish.
Opportunistic Exploration
Anyone familiar with ocean exploration knows that things don’t always go as planned. So, when the weather forced the team to move the ship out of the planned operating area to the western side of the island of Hawaiʻi where they could safely continue their work, they needed a new plan. After consulting with the U.S. Geological Survey’s (USGS) Volcano Observatory, they decided to target the western submarine flank and southwest rift zone of Mauna Loa volcano — the largest active volcano on Earth — both of which were poorly and inconsistently mapped and characterized.
Following the second engineering dive, they mapped the first target near Kealakekua Bay, a shelf with several radial vents and the site of the 1877 Mauna Loa eruption. The next day, they mapped a portion of the second target off South Point. The USGS was appreciative of these data, which provide a consistent bathymetric surface for assessing change in these geologically active areas over time and can help scientists better understand the threats posed by the volcano as well as the submarine growth of Mauna Loa and other oceanic island volcanoes.
On May 23, 2026, a magnitude 6.0 earthquake, the mainshock of a sequence of 42 earthquakes, occurred on the western flank of Mauna Loa immediately inshore of the team’s mapping operations on May 21. As they were still in the area, they conducted some additional mapping, including remapping of a small area, to share with the USGS for their comparative studies.
Map of the multibeam data collected off the island of Hawaiʻi by NOAA Ocean Exploration at the request of the U.S. Geological Survey (USGS) during the 2026 ROV Shakedown expedition. Map courtesy of NOAA Ocean Exploration, 2026 ROV Shakedown. Download largest version (jpg, 1.97 MB).
Getting Things Done
A lot of the action during the 2026 ROV Shakedown expedition happened on Okeanos Explorer, not underwater. Time lost due to weather, mechanical issues with the ship, and supply chain challenges hampered some of the planned operations, but there were still plenty of wins.NOAA Ocean Exploration designs and leads the science operations, but we couldn’t do any of it without our partners from NOAA’s Office of Marine and Aviation Operations (the NOAA Commissioned Officer Corps and professional mariners), the NOAA Ocean Exploration Cooperative Institute, and NOAA’s National Centers for Environmental Information (NCEI). Many of the folks on board for the 2026 ROV Shakedown were new to expeditions on Okeanos Explorer. The ROV and video systems and the networks were also new. This meant a lot of training — including cross-training between mission and ship teams — team building, and familiarization as well as new and updated workflows and standard operating procedures.
Members of the ROV (remotely operated vehicle) Team from the NOAA Ocean Exploration Cooperative Institute with ROV Deep Discoverer during the 2026 ROV Shakedown expedition. Image courtesy of NOAA Ocean Exploration, 2026 ROV Shakedown. Download largest version (jpg, 2.49 MB).
Members of the deck crew of NOAA Ship Okeanos Explorer on the back deck of the ship during the 2026 ROV Shakedown expedition. Image courtesy of NOAA Ocean Exploration, 2026 ROV Shakedown. Download largest version (jpg, 2.67 MB).
Mapping operations were primarily for practice, to build routine and familiarity with the systems for the expeditions to follow. In total, 8,990 square kilometers (3,471 square miles) of seafloor were mapped within the U.S. Exclusive Economic Zone off Hawaiʻi, including the mapping done for the USGS.
Mapping Lead Trey Gillespie, Expedition Coordinator Kasey Cantwell, and Survey Technician Sophie Caradine-Tabor discussing changes to mapping plans in the dry lab of NOAA Ship Okeanos Explorer during the 2026 ROV Shakedown expedition. Image courtesy of NOAA Ocean Exploration, 2026 ROV Shakedown. Download largest version (jpg, 2.43 MB).
Sampling operations focused on cleaning, inventorying, and setting up the wet lab and installing a new sampling data management system developed by NCEI. Samples were only collected to test the sampling workflow and the system. Five primary samples were collected (one geological, four biological).
While there were some technical glitches with the ROVs, that’s what a shakedown is for. Troubleshooting resolved most glitches and served as valuable training opportunities for new ROV team members. Other challenges called for quick thinking and flexibility and meant that some objectives had to be carried over to future expeditions. Nevertheless, the 2026 ROV Shakedown expedition was largely considered a success, with all aboard and onshore looking forward to the rest of the field season.
