The Commander Islands are the western group of the Aleutian Islands, the western extremity and the upper part of a huge underwater volcanic range, which protrudes from east to west for up nearly 2,000 kilometres. They lie in the northern part of the Pacific Ocean, 175 km east of the Kamchatka Peninsula, between latitudes 55o 25’ and 54o 31’ north and longitudes 165o 04’ and 168o 00’ east.