[Mr Quatro]

Originally Posted by Commander Wallace

There have been as Jim said a number of collisions between subs, documented and otherwise unknown. I'm sure the actual number would be astonishing. 40 years later, they felt safe enough reporting it ?

Here's one few people know about: https://en.wikipedia.org/wiki/USS_Von_Steuben_(SSBN-632)

On August 9, 1968, while operating submerged about 40 miles (64 kilometers) off the southern coast of Spain, the USS Von Steuben (SSBN-632) was struck by a submerged tow cable connecting a tug and a merchant tanker called the Sealady (Sealady was a liberty ship previously named Bengt H. Larson (1959) and before that was named Alan Seeger (1954)). Due to the merchant being under tow at the time of the collision, the ship had no engine noise for the submarine to detect its presence. When it became apparent the submarine had lost depth control and steering, but not knowing why, the submarine conducted an emergency main ballast tank blow, which resulted in the collision of the submarine and the towed ship. The submarine suffered external damage to the sail and superstructure. After local repairs at the submarine squadron facilities in Rota, she reported to Groton, Connecticut, for more detailed repairs at the Electric Boat Division of General Dynamics Corporation, after which she resumed deterrent patrols out of Rota.

The Sealady sank in the harbor of Cadiz, Spain in plain sight of the submarine base at Rota.