definitely taking its toll. even locals tell me they now think twice about venturing into old historic san juan especially after dark. for the south american drug cartels these islands are now coveted for location and domestic status. >> deploy to the northeast. >> reporter: it is wheel up yet for another night of high-tech hunting for cocaine smugglers. >> looking at a vessel. >> reporter: on these routine missions this officer with u.s customs & border protection uses infrared radar and intel to alert boats on the water to interdict around the coast of puerto rico. >> before we didn't see as many mother ships coming to puerto rico and dominican republic, now they're becoming ordinary. >> reporter: almost as ordinary, enormous busts like this, so much cocaine it took a production line of people to haul bag after bag from the van to the table.