What happenned next?
The Russian submarine would also have had little chance of detecting the quieter Los Angeles–class submarine. More powerful fixed antisubmarine sensors might only have been effective at ranges of three to five kilometers in such conditions, too short to reach the Baton Rouge’s position. Submarines can also deploy towed sonar arrays behind them to increase their sonar coverage, but these are difficult to control in shallow waters and were therefore not in use during the incident.
It’s tempting to think of sonar as a sort of radar that works underwater. However, water is a far less compliant medium than air even for the most modern sensors, and wind conditions, temperature variations and sounds rebounding off the ocean floor can all dramatically degrade its performance. When attempting to detect the extremely quiet submarines currently in use, just a few adverse factors can turn a very difficult task into an impossible one.
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Therefore, a submarine spying close to an adversary’s home port might not be able to spot another submarine heading towards it until after the collision—which can be worse than embarrassing for everyone involved.
On February 11, 1992, the USS Baton Rouge, a nuclear-powered Los Angeles–class attack submarine, was lurking twenty meters deep in the shallow waters off of Kildin Island, fourteen miles away from the Russian port of Murmansk. The Soviet Union had dissolved just two months earlier—but the Navy still wanted to closely monitor what had become of Russia’s powerful navy.