The Soviets were conducting a surveillance mission of some sort near the base and…whoops! my bad!…ran aground and got stuck.
There was apparently a brief period of Soviet denial ‘Sub? What sub? We don’t have any subs there.’ Followed by the dispatch of a recovery fleet of tugs and armed warships. The Swedes told them they would not be allowed in Swedish waters (which, of course, the Soviets showed all intention of ignoring). The Swedish government then activated some coastal defense batteries and announced they would fire on vessels entering Swedish waters.
Apparently, things got a little tense for awhile and the outbreak of hostilities between the two nations was an actual possibility. Since it was a Whiskey class sub, the incident got the name ‘Whiskey on the rocks’. Quite clever actually.
Just to prove the old Soviet propoganda machine still has some life left in her, here’s how EnglishRussia describes the incident:
On the night of 14/15, October, 1981, Soviet diesel submarine â„–137, was making a usual training voyage in the Baltic Sea. Owing to failure of navigating devices and errors in place definition, it ran off the course in low visibility and took the ground at a southeast extremity of Sweden…