In 1952, the Taiwan Patrol Force, Task Force 72, began conducting surface SIGINT Operations in the Taiwan Straits using destroyers of the Seventh Fleet.
Their purpose was to prevent any attack on or invasion of, Taiwan (formally known as Formosa) and the Pescadores Islands to ensure these islands were not used as a base of operations against the Chinese mainland by the Chinese Nationalists, except in the event of a Chinese Communist attack. In early February 1953, as the result of a major U.S. policy change, the latter part of the above mission was delayed.
In the early 1960s, the Soviet navy began operating more extensively outside its coastal waters, allowing for closer scrutiny of its units by the U. S. Navy. To take advantage of the opportunity to learn more about Soviet operations and the defenses along the Soviet and People’s Republic of China coasts, a series of reconnaissance and surveillance operations was conducted in the Far East, using destroyers or submarine rescue ships (ASR). A small Navy Security Group detachment, with jury-rigged receivers and antennas, were placed in each of the assigned U.S. Navy ships for use while cruising along the Chinese and Soviet coasts. The operations proved so useful and productive that Commander in Chief, Pacific Fleet (CINCPACFLT), proposed to the Chief of Naval Operations (CNO) in February 1965 that a small ship be outfitted to perform signal intelligence (SIGINT) collection as a permanent task. In this way the crews involved would develop expertise in such operation.
The Far Eastern coastal surveillance effort was designed to be completely overt. CINCPACFLT explained the mission of the operations in a September 1965 message as “to determine Soviet reaction to a small unarmed naval vessel which is overtly a naval surveillance ship deployed in Soviet Navy operating areas.” Thus, the surveillance ship was to be perceived as an observation platform wearing the “uniform” of the U.S. Navy, operating in places where it was entitled to be, and in no way disguising its nationality, appearance or function.
Source: A Century of U.S. Naval Intelligence
Edited by Mario Vulcano