Officials say the San Francisco-based cutter McCulloch first set sail during the Spanish American War.
It sank 100 years ago - June 13, 1917 - after colliding with a civilian steamship off Point Conception on the Santa Barbara County coast. The site is about 150 miles northwest of Los Angeles.
The National Oceanic and Atmospheric Administrations and the U.S. Coast Guard provided video of the mission that made the discovery.