Find and Fix: Direction Finding in the Cuban Missile Crisis (Part 4 of 5)

The High Frequency Direction Finding (HFDF) fix in the above message was one of many prosecuted by dozens of U.S. Navy, British, and Canadian direction finding stations in the Atlantic periphery on the days following the President’s initiation of a naval blockade. Matthew M. Aid, in his book, The Secret Sentry, writes:

The two dozen or so U.S. Navy, British, and Canadian direction-finding stations ringing the Atlantic continuously monitored every radio transmission going to or from the twenty-two Soviet merchant ships approaching the Cuban quarantine line, in order to track the movements of the Russian ships… The U.S. Navy’s direction-finding stations began reporting to NSA that their tracking data indicated that some of the Russian merchant ships had stopped dead in the water, and that it seemed that at least eight of the ships had reversed course and were headed back toward Russia.