A GLORIA sidescan survey conducted in 1986 further established the rough size and locations of the seamounts.

A further sampling cruise by the United States Geological Survey (USGS) recovered pillow lava and hyaloclastite from 4 of the 8 volcanoes.

In 1998, the Monterey Bay Aquarium Research Institute conducted two dives on a cone cluster located southeast of the main structure.

The volcanoes form a linear chain, and are relatively small, measuring less than 10 km (6 mi) in diameter, and are nearly circular in shape.

In addition to the eight main seamounts, there is a scattered disk of minor volcanic cones and flows about 13 km (8 mi) southeast of the chain.