The bay has an estimated depth of 30 metres (98 feet), and there is strong evidence of ongoing underwater volcanic activity, as evidenced by frequent bubbles, altered water chemistry and the presence of bacteria mats.

The northern islet (Ryponkicha Russian: o. Рыпонкича) is the smaller of the two, and consists of a portion of the volcano's flank, with sheer cliffs rising up 131 metres (430 feet) from the sea.

[2] Ushishir had no permanent habitation prior to European contact, but was visited in summer by the Ainu tribes from Rasshua, who regarded the island as a sacred land, which they identified as the home of the thunder god.

Approaches to the island are difficult due to frequent fogs, rapid ocean currents and the presence of numerous small offshore rocks.

After World War II, the island came under the control of the Soviet Union, and is now administered as part of the Sakhalin Oblast of the Russian Federation.