In early April 1962, the destroyer USS DeHaven (DD 727) made the first DESOTO Patrol (A) along the northern coast of China from the Taiwan Strait to the vicinity of Tsingtao and back.  Thereafter, the patrols were made on a random basis every month or two into such areas as the Sea of Japan, Gulf of Tartary, the Yellow Sea, South China Sea, and Java Sea.  In December 1962, USS Agerholm (DD 826) extended the patrols into the Gulf of Tonkin.  The presence of DESOTO Patrols in strategically important areas stimulated reactions, which in turn provided an opportunity for intelligence collection.  Particularly noteworthy reactions occurred when these patrols entered an area for the first time in the area of operations.  Highly useful signal intelligence (SIGINT) and photographic intelligence were thus obtained.


In 1963, for the first time, intelligence coverage of the Soviet naval convoy during annual transit of the northern sea route along the northern coast of the USSR was performed.  An icebreaker (AGB) supplied by Commander Alaskan Sea Frontier, with an embarked helicopter, collected valuable intelligence concerning the number, class, and characteristics of the Soviet naval vessels entering the Pacific with the convoy.

A radar picket destroyer escort (DER) was kept in position to maintain close surveillance of the Soviet missile-range instrumentation ships throughout their intercontinental ballistic missile (ICBM) tracking operations in the mid-Pacific from November 1963 to April 1964, inaugurating a policy of maintaining surveillance of such ships by surface craft.

The two peripheral SIGINT missions conducted by destroyers from the Taiwan Strait Patrol Force along the Chinese and North Vietnamese coasts were performed for the purpose of stimulating military reaction, and they afforded unique opportunities to collect electronic intelligence (ELINT) (B),  Foreign Instrumentation Signals Intelligence (FISINT) (C) and photographic intelligence.


During April 1964, the submarine rescue vessel USS Chanticleer (ASR 7) conducted “snooper” operations in the vicinity of Soviet naval operating areas off Vladivostok (Soviet Headquarters Pacific Fleet) and the southern maritime province to collect intelligence information on the Soviet spring naval exercise.  Chanticleer’s operating procedures were not unlike those of the Soviet SIGINT trawlers that had been shadowing U.S. naval operations since the beginning of the 1960s.

Commander Seventh Fleet (COM7THFLT), in January 1964, prescribed the mission of the DESOTO Patrols as being intended “to probe peripheral areas of concern to COM7THFLT and to collect all-source intelligence in order to increase both the COM7THFLT and national fund of information concerning both military and civil activity of the Asiatic Communist Bloc.”  VADM Thomas H. Moorer, COM7THFLT, ordered random cruises to be conducted about once every three months in order to gather intelligence information on Communist air and sea defenses and to make hydrographic and weather observations.  Moorer specified the general track for the patrols but gave commanders flexibility to change course as desirable to collect additional intelligence.  To derive maximum collection on Communist reaction to the patrols, flights by Fleet Air Reconnaissance Squadron ONE (VQ-1) EC-121 Navy SIGINT Reconnaissance aircraft were scheduled to coincide with them.

Chinese Kronstadt-class submarine chaser patrol boat

In mid-February, in response to an urgent request from GEN Paul D. Harkins, Commander U.S. Military Assistance Command Vietnam (COMUSMACV), for radar mapping (ELINT) and photography of the North Vietnamese coasts, the destroyer USS John R. Craig (DD 885), with Commander Destroyer Squadron (COMDESRON) One, CAPT Daniel S. Appleton, embarked, began the first DESOTO Patrol in the Gulf of Tokin under the rules specified by COM7THFLT.  Craig’s orders directed the ship to remain 15 nautical miles off the Chinese coast and 4 nautical miles off the North Vietnamese mainland.  Several days of fog limited visual collection, but much valuable electronic intelligence (ELINT) that fulfilled the ship’s basic mission was collected.  A Chinese Kronstadt-class submarine chaser patrol boat and an unidentified plane shadowed Craig during part of the patrol.  The destroyer completed its patrol on March 8, 1964 and returned to Taiwan as the Chinese Communists issued their 280th “serious warning” of an alleged violation of their territorial waters.


The DESOTO Patrol in the Gulf of Tonkin led to the incident of the same name when torpedo boats attacked the destroyer USS Maddox (DD 731) on the night of August 2, 1964.  On August 4, USS Maddox accompany with USS Turner Joy (DD 951) were believed to have been similarly attacked on August 4.

This incident resulted in the Gulf of Tonkin resolutions that authorized President Lyndon B. Johnson to take any measures he believed were necessary to retaliate and to promote the maintenance of international peace and security in Southeast Asia (Vietnam War!)

On September 12, 1964, CINPACFLT ADM Thomas Moorer recommended another DESOTO Patrol into the Gulf of Tonkin.  CINPAC ADM Ulysses S. G. Sharp approved the plan, and the Joint Chiefs of Staff authorized a three-day cruise to approach no closer than 20 nautical miles to the North Vietnamese mainland and no closer than 12 nautical miles to Communist-held islands, except that the destroyers could approach the 3-mil limit if in hot pursuit of attackers.  At dawn on September 17, the destroyers USS Morton (DD 948) and USS Richard S. Edwards (DD 950), with COMDESRON 52 (CAPT Edward E. Hollyfield) embarked in USS Morton, entered the Gulf of Tonkin.  On the night of September 18, the destroyers were approached by two high-speed targets, which were engaged by both U.S. Navy ships and believed both targets was sunk and destroyed.

(A) DESOTO is named for the USS DeHaven operational signals intelligence (SIGINT) patrol, DeHaven, Special Operations off TsingtaO.   Destroyers equipped with a mobile van of SIGINT equipment were used for intelligence collection in hostile waters.

(B) Electronic Intelligence (ELINT) is information derived primarily from electronic signals that do not contain speech or text.  It is divided into major branches. One branch is Technical ELINT (TechELINT), which describes the signal structure, emission characteristics, modes of operation, emitter functions, and weapons systems associations of such emitters as radars, beacons, jammers, and navigational signals. Another major branch is Operational ELINT (OpELINT), which concentrates on locating specific ELINT targets and determining the operational patterns of the systems. These results are commonly called Electronic Order of Battle (EOB). OpELINT also provides threat assessments, often referred to as “tactical ELINT.” (source:

(C) Foreign instrumentation signals intelligence (FISINT), first known as  Telemetry intelligence (TELINT) was a critical source of performance information on foreign missiles and space vehicles while they were being developed and tested, as well as a source of telemetry from military aircraft during their development. TELINT could also provide much operational information on foreign satellites and space vehicles. The National Security Agency (NSA) became responsible for U.S. TELINT under a Department of Defense directive in 1959 as part of NSA’s ELINT responsibilities. TELINT prior to 1959 was being conducted by all of the DoD military departments. (source:

Source: A Century of U.S. Naval Intelligence
Edited by Mario Vulcano