The volcano has become emergent and then been eroded back into the sea at least eight times since its first recorded eruption in 1939.

The team mapped a roughly conical feature rising from 1,100 m (3,600 ft) water depth, with the volcano having a basal diameter of about 8 km (5.0 mi).

[3][4] When the volcano erupted in 2003, a 15 m-high (49 ft) island formed above the surface, but it disappeared soon after.

[5][6] More recent volcanic activity can be inferred from observations of discolored water around the volcano, in 2020 and January 2021.

[1] In 2015, marine wildlife was found living inside Kavachi's crater, including the scalloped hammerhead, the silky shark, and the sixgill stingray.