2026 Cook Islands ROV Exploration

Overview

With 15 islands surrounded by nearly 2 million square kilometers (770,000 square miles) of ocean, the Cook Islands is a nation of vastly more water than land. And those waters are deep – the average depth of waters within the Cook Islands Exclusive Economic Zone is 5,000 meters (3.1 miles) and in the majority of locations, water depth is greater than 2,500 meters (1.6 miles). With seafloor features that range from seamounts to abyssal plains that contain a variety of marine resources and marine life, those waters are also largely unexplored.

In July and August 2026, NOAA Ocean Exploration, the Cook Islands Seabed Minerals Authority (SBMA), and partners will conduct a 26-day cruise on NOAA Ship Okeanos Explorer to increase our understanding of the seafloor and water column in the deep waters of the Cook Islands, better characterize the resources and ecosystems they hold, and support Cook Islands-led decision-making under Cook Islands law. The 2026 Cook Islands ROV Exploration cruise will include remotely operated vehicle (ROV) dives to explore the seafloor and water column, mapping operations, Argo float deployments, other sensors, and continuous shore-side participation via telepresence technology.

NOAA Ship Okeanos Explorer docked at Ford Island in Hawaiʻi in May 2026. Image courtesy of NOAA Ocean Exploration, 2026 ROV Shakedown. Download largest version (jpg, 6 MB).

Exploration Goals

During the cruise, the team will work to close gaps in our knowledge of the geology, biology, and water column in the region.

• Geology: Scientists will explore seamounts, abyssal plains, and the Manihiki Plateau to fill gaps in seafloor mapping data and study seafloor features. This work will allow comparisons over a variety of seafloor habitat types, documentation of environmental conditions, expanded understanding of the geologic history of the Cook Islands, and informed management decisions about seabed resources.
• Deep-Sea Biology: The team will image and catalog animals on the seafloor and in the water column of seamounts and abyssal plain environments to understand how biological communities vary across different underwater features and assess the distribution, variety, and resilience of animals in the deep waters of the Cook Islands.
• Water Column: Exploration of the water column of the Cook Islands will help to build a basic inventory of the animals living there, provide a framework to describe ocean characteristics at various depths, and build foundational information to better understand oceanic conditions and inform decisions about marine resources in the region.

Operations

During the 2026 Cook Islands ROV Exploration cruise, the team will work to increase our understanding of the region by conducting targeted mapping and ROV operations, with a focus on waters deeper than 200 meters (656 feet), building off work completed as part of the NOAA-funded 2025 Deep-Sea Habitats of the Cook Islands cruise on Exploration Vessel Nautilus.

This map shows the planned area of operations for the 2026 Cook Islands ROV Exploration cruise. Map courtesy of NOAA Ocean Exploration, 2026 Cook Islands ROV Exploration. Download largest version (jpg, 2 MB).

We will use the advanced sonar systems on Okeanos Explorer to fill critical gaps in high-resolution mapping data, including seafloor, sub-bottom, and water column data. Collected mapping data will inform cruise ROV dive targets and guide future exploration efforts, help to understand the current state of the ocean environment, identify knowledge gaps, increase understanding of marine resources and their environmental contexts to inform management decisions, and increase public awareness of ocean issues.

Over the course of the expedition, we will conduct ROV dives at depths ranging from approximately 2,500 to 6,000 meters (1.6 to 3.7 miles) to explore habitats at seamount, knoll, and plateau features. Thanks to telepresence technology, anyone with an internet connection is invited to watch and listen as members of the science community actively engage and guide each dive.

All things permitting, dives will be streamed live daily, July 20 to August 11. Note that dates and times are subject to change.

Other tools, including CTD (conductivity, temperature, and depth)-mounted sensors, an acoustic Doppler current profiler (ADCP), expendable bathythermograph (XBT) probes​, collected water samples, and Argo floats will help us to assess physical, biological, and chemical conditions of the seafloor and water column, providing insights into environmental processes and ecosystems. During the expedition, we will also collect a limited number of geological and biological samples using the ROVs, following NOAA Ocean Exploration’s sampling philosophy for Okeanos Explorer.

This sea cucumber, imaged during the Deep-Sea Habitats of the Cook Islands expedition in 2025 on Exploration Vessel Nautilus, is part of the Family Psychropotidae (deep-sea swimming sea cucumbers), which is found deep into the abyssal zone. Image courtesy of Ocean Exploration Trust, DeepSea. Download largest version (jpg, 1 MB).

Partnerships and Collaborations

This cruise is a partnership between the U.S. and Cook Islands governments, including NOAA, the Seabed Minerals Authority, the U.S. Department of State, the U.S. Geological Survey, and the Ocean Exploration Cooperative Institute. This collaboration aims to better understand the region’s deep-sea environments, with the collected scientific data supporting the Cook Islands government and all Cook Islanders in making informed management decisions about their resources based on scientific evidence.

The cruise is a scientific exploration and mapping activity that supports the Cook Islands’ understanding of its deep ocean. It will help build baseline knowledge of areas that remain difficult to access and not well understood. The cruise does not authorise commercial seabed minerals harvesting and does not replace Cook Islands law, public process, or environmental safeguards.

NOAA Ocean Exploration is committed to ensuring full and transparent access to cruise knowledge and findings for local communities, decision-makers, and the scientific community. Dive operations will be streamed live and regular updates provided on the oceanexplorer.noaa.gov website while the cruise is underway. After the cruise, collected data will be provided to the Cook Islands government and will be filed in the public domain, meaning it will be available to anyone through the NOAA data archives.