Protector Shoal is a submarine volcano, also called seamount, which rises gently from an ocean depth of 1200 metres to about 27 m (90 ft) below sea level 56 km to the northwest of Zavodovski Island in the South Sandwich Islands chain. The last eruption occurred during March 1962. Protector Shoal is the only volcano in the arc that has erupted rhyolite pumice.