Beyond the Blue: 2025 ROV and Mapping Shakedown

Science Highlights

While each dive had engineering objectives, they also addressed scientific objectives put forward by NOAA scientists and partners and the broad ocean science and management communities.

In partnership with SEARCH, the Air-Sea Heritage Foundation, the Naval History and Heritage Command, the University of Hawaiʻi, and the Ocean Foundation, NOAA Ocean Exploration explored two World War II-related maritime heritage sites.

• LST-884: After significant effort to locate the target in the multibeam backscatter data, Dive 03 explored the wreck of the U.S. Navy’s amphibious warfare ship (landing ship tank) LST-884. LST-884 participated in the invasions at Iwo Jima in February 1945 and Okinawa in April 1945. On the first day of the latter, LST-884 sustained serious damage from a Japanese kamikaze attack. It was towed back to the United States and decommissioned and scuttled off south Oʻahu, Hawaiʻi, in 1946. LST-884 was first located and explored by researchers from the Hawaiʻi Undersea Research Laboratory who found it while surveying the area for historically significant World War II-era shipwrecks and naval assets in 2014.
• USS Nevada: Dive 06 explored the remains of the U.S. Navy’s legendary battleship USS Nevada (BB-36), which took part in both World War I and II. Nevada survived the attack on Pearl Harbor, participated in the invasions at Normandy, Iwo Jima, and Okinawa; and withstood two atomic bomb tests. In 1948, it was deliberately sunk after being used as part of a naval weapons testing exercise southwest of Honolulu, Hawaiʻi. At 4,683 meters (almost three miles) below the surface of the ocean, this dive was the deepest maritime heritage exploration ever conducted during expeditions on Okeanos Explorer and by NOAA Ocean Exploration, at the time. Nevada was first located by SEARCH and Ocean Infinity in 2020.

At the request of Hawaiian Islands Humpback Whale National Marine Sanctuary’s managers, Dive 04 explored an area just outside the sanctuary, collecting data to help them better understand the deep waters around it. During this dive, representatives from the sanctuary joined the livestream from ship and shore to talk about its significance.

General scientific objectives included capturing video and collecting biological, water (for environmental DNA (eDNA) analysis), and geological samples to better understand the marine life and geological context of the region.

Corals (octocorals, black corals, stony corals) and sponges (glass, carnivorous) were seen on most of the dives. Other animals seen during these dives included anemones, echinoderms (sea cucumbers, brittle stars, brisingid sea stars, crinoids, sea urchins), arthropods (shrimp, squat lobsters, crabs), benthic ctenophores, octopods, and a variety of fish.

Sahara Rios-Bonilla and Danielle Warren retrieving water samples from remotely operated vehicle Deep Discoverer. Water samples were collected at depth and filtered for environmental DNA (eDNA) in NOAA Ship Okeanos Explorer’s wet lab during the 2025 ROV and Mapping Shakedown expedition. Image courtesy of Caitlin Bailey, Global Foundation for Ocean Exploration, 2025 Beyond the Blue. Download largest version (jpg, 2.07MB).

Geological features observed included basaltic lava boulder fields, scarps, rock walls and outcrops, and loosely sedimented seafloor.

Small caverns in a rock outcrop. This interesting geological formation was seen on Penguin Bank during Dive 04 of the 2025 ROV and Mapping Shakedown expedition. Image courtesy of NOAA Ocean Exploration, 2025 Beyond the Blue. Download largest version (jpg, 2.19 MB).

Collecting a geological sample. Collected during Dive 05, this igneous black basalt rock was the only geological sample collected during the 2025 ROV and Mapping Shakedown expedition. Image courtesy of NOAA Ocean Exploration, 2025 Beyond the Blue. Download largest version (jpg, 2.55 MB).

Wrapping Up the Shakedown

While the primary objective of this expedition was to verify mission system readiness for the 2025 field season — ensuring operational reliability and safety and data integrity — the mission’s impact extended far beyond technical verification.

Beyond confirming the readiness of critical systems, the expedition served as a vital training and skill-building opportunity, allowing new and returning team members to develop and practice ROV operations-related skills. In addition, it yielded important baseline data that will drive future exploration and research and inform regional resource management decisions.

The 2025 field season on Okeanos Explorer is off to a great start!