The destroyer USS O'BANNON (DD 987) leads U.S. and Chilean navy vessels taking part in Unitas XXXII, a combined exercise in volving the naval forces of the United States and nine South American nations. To port of O'BANNON are the Chilean frigate CONDELL (06) and the guided missile destroyer USS DAHLGREN (DDG 43); to starboard, the Chilean destroyer ALMIRANTE RIVEROS (18), the guided missile frigate USS AYLWIN (FF 1081), the Chilean frigate LYNCH (07) and the Chilean training ship URIBE (29); to rear, the tank landing ship USS BARNSTABLE COUNTY (LST 1197) and Chilean tank landing ship MAIPO (94)