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The image depicts a remotely operated underwater vehicle (ROV) illuminating a section of the ocean floor. The ROV’s bright lights cast a blue glow on the textured seabed, highlighting its rough surface. The surrounding water is a deep blue, fading into darker shades as it extends away from the light source, creating a sense of depth.

2026 American Samoa ROV + Mapping Exploration

Dive 12: South Samoa Basin Seamount

September 11, 2026

Location: Lat: -16.314713449°; Long: -168.111670596°  
Dive Depth Range: 3,070-3,262 meters (1.91-2.03 miles)
View dive images and videos

The final dive of the 2026 American Samoa ROV + Mapping Exploration expedition took place on a seamount in the Samoa Basin, approximately 120 miles south of Rose Atoll. The dive started at a depth of 3,260 meters (2 miles) and traversed up a ridge on the southeastern slope of the seamount. The substrate during the dive was primarily ferromanganese-encrusted outcrops, boulders, and cobbles, interspersed with polymetallic nodules and patches of sediment. We also observed volcanic pumice, pillow lava flows, and small ferromanganese-encrusted rock mounds with a very unique texture. We saw a variety of marine life during the dive, including numerous sponge species, a few corals with the dominant species being Ramuligorgia militaris, several large seven-armed brisingid sea stars, crinoids, ophiuroids, xenophyophores, scalpellid barnacles, a grenadier fish with an isopod parasite, and several small arthropod species.

A pink crinoid attached to a tall tan sponge stalk against a dark, rocky ocean floor.

This large senesced sponge stalk provided habitat for a brisingid sea star, crinoids, a Poliopogon sp. sponge, a barnacle, and small amphipods. Seen during Dive 12 of the 2026 American Samoa ROV + Mapping Exploration expedition at a depth of 3,226 meters (2 miles). Image courtesy of NOAA Ocean Exploration, 2026 American Samoa ROV + Mapping Exploration. Download largest version (jpg, 571 KB).

An illuminated remotely operated vehicle observes a large sponge on a dark ocean floor.

During Dive 12 of the 2026 American Samoa ROV + Mapping Exploration expedition, we saw a diversity of glass sponges, including this stalked Caulophacus sponge that was more than 3 meters tall (9.8 feet). To give you a sense of the sponge’s size, in this image, remotely operated vehicle Deep Discoverer shines its light on the sponge; Deep Discoverer is 2 meters (6.4 feet) wide! Image courtesy of NOAA Ocean Exploration, 2026 American Samoa ROV + Mapping Exploration. Download largest version (jpg, 583 KB).

Dark, rounded rocks densely packed on the ocean floor with light sand in the crevices.

Feeding trails through the sediment on these ferromanganese-encrusted rocks seen during the final dive of the 2026 American Samoa ROV + Mapping Exploration expedition intrigued the scientists. Upon closer observation, the source of feeding trails on the rocks was a monoplacophoran, a kind of mollusc. Image courtesy of NOAA Ocean Exploration, 2026 American Samoa ROV + Mapping Exploration. Download largest version (jpg, 930 KB).

A red sea cucumber resting on white sand among dark rocks on the ocean floor.

This red Synallactid sea cucumber with thin papillae was seen feeding on sediment at a depth of approximately 3,200 meters (2 miles) during Dive 12 of the 2026 American Samoa ROV + Mapping Exploration expedition. Image courtesy of NOAA Ocean Exploration, 2026 American Samoa ROV + Mapping Exploration. Download largest version (jpg, 934 KB).

An ROV collection basket and mechanical arm positioned above dark, rounded rocks on a sandy ocean floor.

A box full of rocks! Several rocks were collected and carefully stored in the rock box on remotely operated vehicle Deep Discoverer during Dive 12 of the 2026 American Samoa ROV + Mapping Exploration expedition. Image courtesy of NOAA Ocean Exploration, 2026 American Samoa ROV + Mapping Exploration. Download largest version (jpg, 841 KB).