Soviet submarine K-33

The K-33 was a Soviet nuclear-powered Project 658 class submarine (NATO reporting name "Hotel II"). She belonged to the Soviet Northern Fleet and carried the identification number 921. In 1977, she was renamed K-54.

K-33 was built at Factory No. 902 in Severodvinsk, Soviet Union, as a Hotel I class submarine, launched on 6 August 1960 and was commissioned on 5 July 1961. In 1964 the K-33 was repaired and modernized into "658M"-standard (Hotel II), by installing a new missile complex giving her capability to fire missiles while submerged. She was decommissioned in 1990.

K-33 was involved in two incidents.

Kattegat incident
On 12 April 1963 the K-33 collided with the Finnish merchant vessel M/S Finnclipper in Kattegat.

The M/S Finnclipper, which was owned by Enso Gutzeit was on its way to the United States with a load of 6,000 tons of paper. When they reached Kattegat, there was a mist. The crew heard engine noise on their port side at 11.05 am and a submarine emerged. The Finnclipper steered heavily to starboard to try to avoid a collision, but to no avail.

The Finnclipper immediately stopped and returned to the submarine to see if it needed help. Two Russian officers on board told the Finnish captain that the side had received large structural damage and that the side had been pressed in and had become deformed. The Soviet officers did not reveal their nationality, but told that it was a Warsaw Pact submarine. The Finns could however read the number 921 clearly on the side of the submarine.

The K-33 had been on its way to a patrol in the North Atlantic. The Finnish vessel managed to cross the Atlantic ocean although she had sprung a leak. The K-33 limped to Murmansk although she was severely damaged. The captain of the Finnish vessel, Runar Lindholm, gave a maritime declaration when arriving in New York, but the report was labeled secret for over 44 years. The Soviets claimed that it was not a nuclear submarine, although she had been clearly identified. It has been speculated that the incident was held secret due to the Soviet-Finnish YYA-treaty, where the Soviets would have forbid the Finns to report this in the news media or even to research the incident.

On 4 April 2007, the Finnish captain and maritime author Jaakko Varimaa, who at the time was Second Mate on the Finnish vessel, published his book Sukellusvene sumussa ("Submarine In The Mist") revealing the accident.

However, according to some Russian sources at the time of this collision the K-33 was on overhaul in the Russian Northern Fleet, which lasted from October 25, 1962 through December 29, 1964. Later in this article it says that the K-33 was en route to a patrol in the Atlantic.

Arctic incident
In 1965, the K-33 was involved in a radiation emergency in the Arctic, involving dehermeticity of fuel elements.