The Record
American Skipjack-class nuclear attack submarine, returning to Norfolk from the Mediterranean. Vanished somewhere southwest of the Azores on 22 May 1968. 99 dead; the wreck was located five months later at 3,050 metres. The most supported theory is that one of her own Mk 37 torpedoes activated inside the tube and detonated against the inner door, though alternative explanations involving Soviet retaliation for the March loss of K-129 have never fully faded.
The Vessel
USS Scorpion (SSN-589) was a Skipjack-class nuclear attack submarine, the fifth of six built to the original Skipjack design between 1957 and 1960. She was commissioned on 29 July 1960 at the Electric Boat yard in Groton, Connecticut, was 77 metres long, 3,500 tons submerged, and powered by a single S5W reactor driving a single seven-bladed propeller on a single shaft: a simpler and cheaper configuration than the Permit-class that succeeded her.
Her class had been the first American submarine design to combine the Albacore teardrop hull with nuclear power, a marriage of speed and endurance that set the template for every attack submarine of the following forty years. The Skipjacks were as fast submerged as the previous generation had been on the surface, perhaps 30 knots, and they could maintain that speed for their reactor life rather than for a battery charge. They were also relatively noisy by the standards of the Permit and Sturgeon classes that would follow; the single-shaft seven-bladed propeller was a characteristic Skipjack sound signature that Soviet intelligence eventually learned to recognise.
Scorpion served through the 1960s in the Atlantic Fleet, based at Norfolk, operating in the Mediterranean, the North Atlantic, and the approaches to the Barents and White Seas. Her 1967-1968 Mediterranean deployment, her last, included an intelligence-surveillance patrol shadowing Soviet naval units including the May 1968 loss of the Soviet submarine K-129 in the Pacific; American intelligence had speculated at the time that Soviet retaliation for the K-129's fate might be directed at an American boat in Atlantic waters.
The Voyage
She departed Rota, Spain, on 16 May 1968 for Norfolk on a direct return passage. She was due at Norfolk on 27 May. Her commanding officer was Commander Francis Slattery, 36, a career submariner and Naval Academy graduate. Her crew was 99: 12 officers and 87 enlisted.
Her routing was through the Azores on a great-circle course toward Chesapeake Bay. Her communications schedule with COMSUBLANT called for a daily position report; she reported on each day of the eastward voyage through the Mediterranean and on her Atlantic approach through the Strait of Gibraltar. Her last reliable acoustic position fix, recorded by a U.S. Navy SOSUS (Sound Surveillance System) station chain in the Atlantic, placed her at 32°54.66′N 33°15.45′W at 18:59 UTC on 22 May 1968, proceeding on course to Norfolk.
At 18:59:27 UTC on 22 May 1968, the Canary Islands hydrophone array recorded a single acoustic transient consistent with the catastrophic flooding of a submarine pressure hull. Eight further acoustic transients followed over the next three minutes, consistent with the collapse of compartment bulkheads as the submarine descended beyond crush depth. The transients were not recognised at the time as a Scorpion loss; they were recorded routinely and archived.
The Disaster
Scorpion failed to make her 27 May 1968 arrival at Norfolk. The U.S. Navy declared her missing on 27 May and initiated a large-scale search in the western Atlantic over the following three weeks. The search was concentrated in the wrong area: the Navy did not know on 27 May that SOSUS hydrophone data from five days earlier had captured the sound of her sinking.
The SOSUS acoustic review, conducted in early June 1968 under Dr. John Craven of the Navy's Deep Submergence Systems Project, identified the 22 May transients as consistent with Scorpion's loss at the corresponding position. The Navy redirected the search and located the wreck on 29 October 1968 by the oceanographic research ship USNS Mizar at a depth of 3,050 metres, 700 kilometres southwest of the Azores.
The cause of the loss has never been officially established with finality. The Court of Inquiry's 1969 classified report concluded that the evidence "did not permit definite conclusions" and offered several possible scenarios: a hot-run torpedo (a Mark 37 that activated inside its tube and detonated); a hydrogen explosion in the battery; a seawater leak in the trash disposal unit; a collision with a Soviet submarine. The hot-run torpedo hypothesis is the one most supported by the acoustic evidence and by the investigation of the wreck's configuration, and it is the unofficial consensus of the American submarine community, though the Court of Inquiry declined to make this an official finding.
99 men died, including Commander Slattery. No bodies were recovered. The Scorpion lies broken into two main sections, her bow and her stern, separated by some distance across the Atlantic abyssal plain.
The Legacy
The wreck has been visited periodically by the U.S. Navy since 1968, most extensively by the bathyscaphe Trieste II in 1968 and 1969 and by the submersible Sea Cliff in 1986. These visits have been conducted under strict classification because Scorpion carried two Mark 45 ASTOR nuclear-armed torpedoes at the time of her loss; the torpedoes, along with her nuclear reactor, remain on the Atlantic seafloor.
Environmental monitoring by the Navy and the National Oceanic and Atmospheric Administration has measured the corrosion rate of the reactor compartment at the Scorpion site since the late 1980s. The reactor itself is contained within the submarine pressure hull and a separate reactor compartment vessel; the nuclear materials have remained contained to date. Sediment sampling in a cylinder around the wreck has shown low background radiation levels consistent with cosmic-ray reference. The Navy's commitment to continuing environmental surveillance at the site is open-ended.
The Court of Inquiry's report was declassified in 1993 and again, with fewer redactions, in 2019. The more complete 2019 release supported the torpedo-malfunction hypothesis with acoustic evidence that had been withheld in 1969 for reasons related to SOSUS classification. The surviving families received the 2019 documents under a joint release programme with the Navy. The Court's final judgment, that no definitive conclusion was possible, has not been revised.
Scorpion was the second and last American submarine lost at sea in the twentieth century. The 99 names are inscribed on a memorial at Arlington National Cemetery alongside the 129 of USS Thresher lost five years earlier; the two crews share a single monument. The inscription reads: In memory of the men of the United States Navy submarines Thresher and Scorpion. Sailors, rest your oars.