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A translucent jellyfish swims above a textured ocean floor covered in dark, round formations, set against a dark background.

2026 Cook Islands ROV Exploration

Dive 08: B2 Seamount

July 28, 2026

Dive 08 took place in western Cook Islands on “B2 Seamount”, starting at a depth of approximately 3,700 meters (2.3 miles). We worked our way up the slope of the seamount, which rises to a depth of 2,400 meters (1.5), documenting the biology and geology of the seamount along the way. During the dive, we observed transitions between seafloor covered with small, densely packed polymetallic nodules approximately 1-2 centimeters (inches) in diameter and bulbous, ferromanganese oxide-encrusted basalt. Marine life we saw during the dive included numerous types of sponges, sea stars, shrimp, sea cucumbers, and other invertebrates.

An underwater scene featuring a rocky seabed on the left transitioning to a sandy floor on the right, illuminated by soft blue and teal tones.

The two dominant types of substrate encountered during Dive 08 of the 2026 Cook Islands ROV Exploration cruise are visible here—larger, rounded, manganese-encrusted basalts in the background and densely packed polymetallic nodules in the foreground. Image courtesy of NOAA Ocean Exploration, 2026 Cook Islands ROV Exploration. Download largest version (jpg, 1.5 MB).

An orange sea star with feathery arms rests on a dark rocky seabed covered in sand and pebbles.

This brisingid sea star was seen clinging to a boulder during Dive 08 of the 2026 Cook Islands ROV Exploration cruise. Image courtesy of NOAA Ocean Exploration, 2026 Cook Islands ROV Exploration. Download largest version (jpg, 1.4 MB).

An underwater cylindrical device with a pink ring is hovering above a textured sea floor covered in small, dark, spherical shapes, with sediment rising around it.

Remotely operated vehicle Deep Discoverer prepares to collect a sediment push core from a seafloor covered in polymetallic nodules seen on the seamount explored during Dive 08 of the 2026 Cook Islands ROV Exploration cruise. Each nodule was about 1-2 centimeters in diameter. Image courtesy of NOAA Ocean Exploration, 2026 Cook Islands ROV Exploration. Download largest version (jpg, 1.5 MB).

A translucent glass sponge with a bulbous bell and long stem, floating against a dark underwater background.

A close look at a glass sponge seen during the eighth dive of the 2026 Cook Islands ROV Exploration cruise. We saw several sponges during the dive, affixed to nodules and rocks. Image courtesy of NOAA Ocean Exploration, 2026 Cook Islands ROV Exploration. Download largest version (jpg, 908 KB).

An orange shrimp swimming against a dark background, with long antennae and legs displayed prominently.

This red shrimp was seen swimming through the water column just above the seafloor during the 2026 Cook Islands ROV Exploration cruise. Image courtesy of NOAA Ocean Exploration, 2026 Cook Islands ROV Exploration. Download largest version (jpg, 850 KB).