Historians may tell you that a NATO fleet has never declared DEFCON 1. But author Chris Styles claims he has evidence a 19-ship fleet went into full panic mode in October 1960. He writes that four separate veterans say the fleet discovered multiple UFO-type flying saucers — alien spaceships — hiding deep underwater.

Investigative journalist Chris Styles first noticed something odd in the logbook of a NATO mine-laying practice mission. In October 1960, 10 U.S. Navy ships and nine Royal Canadian Navy ships set out on a massive training exercise. The lead ships practiced laying fake mines in the ocean. The sweeper ships following behind to practice scanning for and clearing them.

By Oct. 12, this NATO fleet was sailing off the coast near Shelburne, Nova Scotia. Then “all hell broke loose.”

According to the logbook of the commanding ship, the HMCS Cape Scott, the fleet went on an unprecedented DEFCON 1 alert. While sweeping for mines, the fleet had discovered something else underwater — something moving. It had deployed RCN clearance divers to investigate. The divers had returned with an unbelievable report. Styles later interviewed three divers and one RCAF crash-debris specialist.

“There was no doubt what we were dealing with off of Shelburne. There were UFOs sitting on the seabed. They were occupied and there was still activity. One was trying to help the other, which was damaged. They ordered us to the surface and ordered us to forget what we’d seen. Then the alarms sounded upon the command ship and panic broke out,” — Styles quotes in Clear Sweep 5: NATO’s UFO Encounter.

Technically, the witnesses were describing unidentified submerged objects, or USOs.

One intriguing aspect of this 1960 encounter is that it would be years before alien spaceships shaped like flying saucers would become the widespread cultural icon they are today. So the divers may have been less influenced by pop culture than modern divers would be.

Alien spaceship or a scary encounter with a Soviet submarine?

Styles also says he interviewed an Air Force veteran who listened to these divers discuss the flying saucers lying on the ocean floor beneath the ship every night for the rest of the mission. But after the mission, a U.S. Navy officer insisted the object wasn’t an alien spaceship. The divers, he said, had mistaken a “Soviet submarine” for something else.

While NATO hasn’t declassified records — such as the materials recovered from this object or the film footage divers captured — USO sightings continued. In the now-infamous 1967 Shag Harbor incident, eyewitnesses claimed to watch a UFO crash into the ocean just 25 miles from Shelburne.

In 2004, U.S. Navy pilots Cmdr. David Fravor and Lt. Cmdr. Alex Dietrich witnessed and videotaped a Tic Tac-shaped UFO crossing from the ocean into the air off the coast of San Diego. The Pentagon has since established the All-domain Anomaly Resolution Office (AARO) to investigate. Cmdr. Fravor even testified before a House Oversight Committee.

AARO has compiled reports and data of these sightings across the decades. But the sort of high-resolution footage captured during the “Tic Tac incident” hasn’t been possible until recently. Perhaps using this latest information to re-evaluate incidents such as Shelburne and Shag Harbor will help us discover whether witnesses were just looking at a Soviet submarine — or something else entirely. You can see Cmdr. Fravor’s testimony in the video embedded below: