Scientists for the first time have sent a three-man submarine deep into the depths to explore an undersea volcano that nourishes a unique variety of marine life.

The vessel Pisces V visited Cook seamount, a 13,000-foot extinct volcano, earlier this month to examine its geological features. An Associated Press reporter was given exclusive access to the dive.

The researchers from the University of Hawaii and the nonprofit group Conservation International spotted wonders such as a rare type of octopus with big fins that look like Dumbo’s ears, and a potentially new species of violet-hued coral they dubbed Purple Haze.

Conservation International hopes to study 50 seamounts, or undersea volcanoes, over the next five years. They are hotspots for marine life because they carry nutrient-rich water upward from the sea floor.