7 mi. ESE of Cape Kunmik, in Pacific Ocean, Aleutian Range. 0.5 mile long.
Name shown as "O(strov) Gidra," or "Hydra Island," by Captain Tebenkov (1852, map 22), Imperial Russian Navy (IRN), and is shown as "Zatschra Island" on a manuscript Russian map of Kodiak (1849). An 1888 U.S. Bureau of Fisheries (USBF) chart shows "Hydra Island," apparently identical with "Otter Island," shown on a 1900 US@C&GS chart.
Cape Kunmik, Cape Kuyuyukak, Foggy Cape,
Cliffs:Islands:Central Island, Hydra Island, Sutwik Island, Ugaiushak Island,
Streams:Home Creek, Misery Creek, North Fork Yantarni Creek, Yantarni Creek,