Crazy Ivan is a US Navy term for a Soviet submarine maneuver, characterized by any number of sudden and sharp turns, used by submarine crews to "look behind" them. Due to the acoustic distortions and noise caused by propeller blades, it is near-impossible to use conventional sonar behind a submarine. With the sudden turns, the area where the sonar is not effective shifts relative to the current heading of the submarine, causing previous gaps in sonar coverage to be revealed while masking known areas.

The Crazy part of the name comes from the fact that these maneuvers were very sudden and Ivan, of course, was a common nickname used to refer to the Russians. A standard tactic of U.S. Navy submarines would be to closely follow a Soviet submarine right in the sonar gap, causing the U.S. submarine to go undetected. Because of this, there were two dangers for the submarine crews. The first would be, of course, detection by the Soviet submarine as the sonar gap would shift and the U.S. Navy submarine would be revealed. A common countermeasure was to stop the engine and pumps in the pursuing sub and rapidly go for maximum silence, which would lead to the second danger, collision. Due to inertia, the U.S. sub would continue its forward movement with the possibility of collision with the unknowing Soviet submarine dead ahead and making sudden sharp turns.

An example of Crazy Ivan gone wrong happened on June 20, 1970, when the USS Tautog collided with a Soviet Echo class submarine. Fortunately, both boats survived the collision.

The Crazy Ivan phenomenon is used as a plot device to add tension to The Hunt for Red October, a book by Tom Clancy and the subsequent movie of the same name.

On 20 March 1993, the USS Grayling (SSN-646) collided with a Russian Delfin-class ballistic missile submarine.

See also Baffles (submarine).

References

Crazy Ivan: A True Story of Submarine Espionage by W. Craig Reed, William Reed, (ISBN 0595265065)

external links

• Submarines, Secrets, and Spies where Commander Whitey Mack is interviewed and the subject is mentioned.
• A Kursk web site mentioning the Crazy Ivan Manoever
• Chapter about a maneuver