In Memoriam - USS F-1 (SS-20) - Sunk 17 December 1917

On the morning of 17 December, 1917, USS F-1 (SS-20), along with her sister ships F-2 (SS-21) and F-2 (SS-22), got underway for an engineering test. The plan was to steam south from San Pedro to Point Loma, then return. The submarines, designed in the early 1900s and commissioned in 1912 could only make 10 knots on the surface. The round trip was scheduled to take about eight hours.

Since heavy fog is common off the California coast in winter, the plan for the engineering test included a contingency plan for the three submarines to turn to seaward if they ran into poor visibility.

F-1 was closest to the shore, with the other two submarines to her west.

About 1830, the three submarines encountered the expected thick fog. F-1 turned slightly west and sent a radio message to the other two submarines reporting her course change. Unfortunately, this message was not received by the other two boats. F-3 continued on her course south, and F-1 passed behind her, unseen.

At 1904, F-3 began turning to starboard with the plan of reversing course to the north to quickly exit the fog bank.

Eight minutes later, F-1's lights were spotted. The two submarines were on a collision course with a combined speed of nearly 20 knots.

Despite last minute maneuvers by both submarines, F-3 struck F-1 at nearly a right angle, near the bulkhead between the control room and the engine room.

The four men on F-1's makeshift bridge were thrown into the water. A fifth man manged to climb out of the control room, but he was the only one to get out of the doomed submarine.

Nineteen men perished in the accident.


In October, 1975, USNS De Steiguer (T-AGOR-12), an oceanographic research ship, located in 635 feet of water. The hull is laying on its starboard side, with the hole made by F-3 clearly visible.

Photographs courtesy of the U.S. Naval Historical Center.