In 1968, four submarines from four different countries mysteriously vanished in a four-month period (January-May.) Two were in the Mediterranean Sea, one was in the Pacific Ocean, and one was lost in the Atlantic Ocean. One of the four submarines was never found. The other three were found but the cause of their loss remains a mystery. No connection has been made between the four subs, and it is likely a coincidence; however, two of the subs may have been involved in unfriendly action between the United States and the USSR.

These are the four submarines that were lost:

25 January 1968
Isreali submarine INS Dakar was purchased from the British Navy and was sailing from Britain to Isreal. Its last reported position was in the Mediterranean Sea near the island of Crete. Isreal lost contact with the sub and it was never found until 1999. Loss of 69 sailors. The sub experienced explosive decompression when it sank through its maximum structural depth. Cause:  UNKNOWN.

27 January 1968
French submarine Minerve reported that it was one hour from returning to its berth in Toulon, France. Her position was in the Mediterranean Sea, but over 2,300 km (1,450 mi.) away from the Isreali sub lost two days earlier. The Minerve did not return and has never been found. The weather conditions were extremely bad. Loss of 52 sailors. Cause:  UNKNOWN.

8 March 1968
Soviet strategic ballistic missile submarine K-129 last report was on 24 February 1968. It had conducted a test dive near its base in Kamchatka, USSR and surfaced to report that the test went well. It then was to proceed to its patrol in the Pacific Ocean in an area northwest of Hawai’i. It did not report in as scheduled again.

On 8 March, the United States SOSUS net recorded a single loud underwater event northwest of Hawai’i, but the Soviets had no audio net in the Pacific, and they were not aware of the event.

By mid-March, the Soviet Navy became concerned about K-129 and initiated a massive search during the third week of March, but did not find any trace of the sub. The United States began a low profile search based on the location of the SOSUS event and in August, the United States Navy located the sub on the bottom at almost 5,000 meters (16,000 ft.) depth. The CIA attempted to raise the sub and only was able to bring a small section to the surface; however, the Atomic Energy Commission has reported that two nuclear missiles were recovered in the area of the K-129 sinking. The CIA has classified all documents related to the event and has refused all requests for disclosure.

There can be little doubt that the CIA knows the cause, or at least, the probable cause of the loss of USSR’s K-139. The CIA also knows its exact location. 98 crew members were lost. Cause:  CIA will not disclose.

22 May 1968
Near midnight of 20/21 May the USS Scorpion sent a weak message indicating it was about to begin observations on Soviet ships near the Azores in the Atlantic Ocean. It was the last message from the submarine. It was due in Norfolk, VA on 26 May, and the United States Navy announced a search after it failed to arrive; however, there is evidence that the Navy began a search for the USS Scorpion soon after 21 May, indicating that they knew the sub was in trouble or was lost.

The USS Scorpion was found in October of 1968. Its hull was crushed, presumably because it exceeded the maximum depth its structure could withstand. Its crew of 99 were lost. Cause:  UNKNOWN.