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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 01: Southern Seamount Crater

August 26, 2026

Location: Lat: -15.9954172465854 ; Long:  -167.8972366369511
Dive Depth Range: 2,432-2,498 meters (1.51-1.55 miles)
View dive images and videos

The first dive of the 2026 American Samoa ROV + Mapping Exploration expedition took place on the crater and rim of a seamount south of Rose Atoll, starting on the floor of the crater at approximately 2,480 meters (1.5 miles) water depth and climbing up to the southeast section of the ridge.

The caldera was covered in a thick layer of sediment and filled with sparse cobble likely composed of volcanic rocks with a thin coating of polymetallic minerals. Biology observed near the caldera floor included two cusk eels (the only two fish seen during the dive), as well as several shrimp. We also observed evidence of possible bioturbation, though the perpetrator did not make an appearance. 

Moving up the slope from the caldera floor to the ridge, we saw volcanic rocks, including pillow lavas and columnar basalts, all of which appeared to be covered in polymetallic minerals. Corals, including black corals, bamboo corals, and corals in the family Chrysogorgiidae, as well as sponges, particularly glass sponges, populated hard substrates. Other marine life seen near the top of the ridge included numerous crinoids, brittle stars, anemones, and sea cucumbers.

To top of the ridge opened up to a large, flat area covered in sediment.

Translucent bamboo coral polyps with delicate tentacles extending from a white stalk in dark water.

A close look at the extended polyps of a bamboo coral seen while exploring a seamount during Dive 01 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, 217 KB).

A pale crinoid extending feathery arms from a central stalk in a light blue aquatic environment.

This crinoid was observed attached to a dead sponge stalk during Dive 01 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, 221 KB).

Robotic arm pushes a clear cylindrical core tube into a sandy, rocky seabed to collect a sediment sample.

Remotely operated vehicle Deep Discoverer is used to collect a push core sediment sample from the floor of the caldera explored during Dive 01 of the 2026 American Samoa ROV + Mapping Exploration expedition. When fully submerged, the push core did not hit hard substrate, suggesting that the sediment depth in the caldera was greater than 30 centimeters (12 inches). Image courtesy of NOAA Ocean Exploration, 2026 American Samoa ROV + Mapping Exploration. Download largest version (jpg, 480 KB).

A red shrimp with long legs and antennae stands on a light sandy seabed scattered with small rocks.

This spider shrimp (family Nematocarcinidae) with long, stilted legs was seen walking on the sediment that filled the caldera of the seamount explored during the first dive 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, 386 KB).

A multi-armed brisingid sea star clings to a dark, heavily textured rocky surface in the deep ocean.

This brisingid sea star was seen clinging to a rock during Dive 01 of 2026 American Samoa ROV + Mapping Exploration expedition. It was one of several sea stars observed during the dive. Image courtesy of NOAA Ocean Exploration, 2026 American Samoa ROV + Mapping Exploration. Download largest version (jpg, 659 KB).

Large, dark, rounded volcanic rocks form a heavily textured mound on the deep ocean floor.

During Dive 01 of the 2026 American Samoa ROV + Mapping Exploration expedition, volcanic rocks, likely columnar basalts, were seen as the remotely operated vehicle moved from the explored seamount’s caldera up to a ridge feature. These rocks provided hard attachment surfaces for animals such as the stalked glass sponge seen extending into the water column in this image. Image courtesy of NOAA Ocean Exploration, 2026 American Samoa ROV + Mapping Exploration. Download largest version (jpg, 382 KB).