USS Seawolf Nuclear Sub USO 1965

On August 11, 1965, USS Seawolf (SSN-575) — one of the US Navy's early nuclear-powered attack submarines — was on patrol in the North Atlantic when sonar operators detected an unidentified contact that began matching the submarine's course, speed, and depth changes in a manner suggesting direct awareness of Seawolf's movements. The contact maintained a consistent tactical position relative to the nuclear submarine for 30 minutes before ascending at extreme speed to the surface and departing aerially. The contact's acoustic signature was completely unlike any known submarine — Soviet or American — in the sonar database. The Commander, Submarine Forces Atlantic (SUBLANT) was notified via FLASH precedence message. The incident was classified at the highest level under the Navy's special nuclear vessel protocols. The targeting behavior — a contact that appeared to deliberately shadow and mirror a nuclear submarine's movements — was considered of extreme national security significance. The Seawolf case became one of the key entries in ONI's classified analysis of unidentified contacts specifically targeting nuclear-powered vessels.