but they sometimes congregated around aircraft carriers conducting air operations of the United States Sixth Fleet in the Mediterranean or United States Seventh Fleet in the western Pacific Ocean, or in suspected patrol areas of ballistic missile submarines. After the Cuban Missile Crisis, the Joint Chiefs of Staff authorized a counter AGI program for United States destroyers to come alongside the AGIs to push against them, foul their screws with steel nets, and focus high power electromagnetic transmitters to burn out the amplifying circuitry of their electronic sensors. The AGI crews then revealed their ship-handling skills using superior maneuverability to evade the destroyers' intentions. This jousting in international waters continued until signing of the U.S.–Soviet Incidents at Sea agreement in 1972. List of spy ships Argentine Navy Chinese Navy: Type 813 spy ship Type 814A spy ship Type 815 spy ship Yuan Wang-class tracking ship Finnish Navy (Decommissioned) French Navy German Navy Indian Navy INS Anvesh** INS Dhruv Italian Navy Royal Norwegian Navy Marjata (1992) Marjata (2014) Polish Navy Russian Navy See also: List of active Russian Navy ships#Special-purpose ships Spanish Navy Alerta Swedish Navy United States Navy: See also Technical research ship (a class of US spy ships of the early Cold War) USS Liberty incident Battle of Amami-Ōshima References Ship types Espionage techniques Espionage devices Signals intelligence