Much more primitive than the fully submersible cocaine submarine seized on July 2, unmanned torpedo subs—like this one seized in Buenaventura, Colombia, in 2008—are filled with contraband and towed underwater behind a fishing boat, doctor and former smuggler Miguel Angel Montoya said in the online documentary Colombian Narcosubs. If approached, smugglers can simply cut a torpedo loose and let it sink—a tactic used by crews of all types of narco-subs. Because most manned cocaine subs stay at the surface, a crew can quickly escape into a raft while scuttling the ship. The simple torpedo sub, though, may be in for a high-tech makeover too. Remote control cocaine torpedoes are believed to be in the works, according to Montoya.