SS Emidio was a 6912-ton tanker of the General Petroleum Corporation (later Mobil Oil), which became the first casualty of the Imperial Japanese Navy's submarine force action on California's Pacific Coast. Emidio was sailing in ballast from Seattle, Washington en route to San Pedro, California. The Japanese submarine I-17 found Emidio off Cape Mendocino on the early afternoon of 20 December 1941 and hit the tanker with five shells from its 14-cm deck gun. Five crewmen were killed and the remainder reached Blunts Reef lightship in lifeboats. A Catalina flying boat of 44 Patrol Squadron attacked I-17 with depth charges, but the submarine dove and escaped. The abandoned tanker drifted north and broke up on the rocks off Crescent City. The bow drifted into the harbor, where it lay until salvaged in 1950. The remains of the hull are still in the harbor, near a commemorative plaque. The site has been declared a California Historical Landmark #497.
- "Del Norte". California Historical Landmarks. Office of Historic Preservation. Retrieved 2005-08-29.
- "The Attack on the SS Emidio". California and the Second World War. The California State Military Museum. Retrieved 16 March 2012.
- "Wreck of the SS Emidio". USA - California - Crescent City. Wikimapia. Retrieved 16 March 2012.
Coordinates: 41°45′1.96″N 124°11′47.95″W / 41.7505444°N 124.1966528°W