The Coast Guard unloaded some 7.5 tons of cocaine confiscated from a drug submarine in Miami Beach on Friday.

The cocaine, worth about $180 million, was captured from a submarine that traffickers had sunk in an effort to elude capture. It was the latest instane of drug traffickers using "narco submarines," vessels used to covertly transport large quantities of narcotics into the United States. Some officials warn that narco subs represent a dangerous development as cartels become more bold and innovative in finding ways to outdo law enforcement. Below are some photos of the confiscated drugs, as well as images of a narco submarine recovered in a previous operation.