Undersea Terrorism

In the western lowlands of Colombia, where a labyrinth of rivers flow through rainforests and man­grove marshes teeming with exotic wildlife, drug smugglers are secretly constructing the next generation of naval craft—­self-­propelled semi-submersible (SPSS) vessels with a range of 1,500 miles and space for up to 15 metric tons of cargo. The SPSS is the new vessel of choice for drug traffickers, says Captain Wade F. Wilkenson, a special assistant to the com­mander of the U.S. Southern Com­mand, but more ominously, it poses a new danger to American national ­security.

Generally built of wood and fiberglass, the primitive submarines have a small conning tower with a ­wave-­top view for steering. They ride low in the water, usually about four to six inches above the waves, almost totally submerged. Piping directs the diesel engine exhaust back toward the vessel’s wake to dilute its infrared signature. Global positioning systems allow crews to navigate without external communications, to avoid signal de­tection. Powerful diesel engines can maintain cruising speeds of more than eight knots, but the boats tend to move slowly to avoid leaving an easily discernible ­wake.

Constructed and manned at a cost of $1 million to $2 million each, five boats, fully loaded, can double the drug traf­fick­ers’ return on investment in all five if just one of them makes it through, Wilkenson writes. A kilo of cocaine costs about $1,800 in Colombia but fetches at least $20,000 wholesale along the U.S. coast, where the drug runners usually rendezvous with dealers offshore. A four- or five-man crew—on board chiefly to ­off­load when they reach their ­destin­ation—­gets fresh air through snorkel tubes. There are bunks, but no sanitary facilities. The vessels are typically used for one-way missions, and can be almost instantly scuttled if a law enforcement vessel is spotted.

SPSS vessels accounted for only one percent of the maritime cocaine flow from South America to the United States in 2006, but were responsible for 16 percent a year later, and were on track to carry more than 30 percent in 2008. Only 10 percent of known or suspected SPSS ship­ments have been inter­cepted. The underwater detection systems that flagged Soviet submarines when they left their home ports during the Cold War have no counterpart off the coast of Colombia. And sonobuoys work at a distance of two to three miles, and only under very good conditions, Wilkenson ­says.

The current rate at which the vessels are inter­cepted is inadequate, he writes. Developing perfect intelli­gence on every shipment or complete imper­vi­ousness in the six-million-square-mile transit zone seems unlikely. But, coordinated with the Colombian navy and marines, inter­diction efforts can focus on the 1,800 miles of territorial waters along the Colombian coast.

With November attacks on tourist hotels in Mumbai by seaborne killers raising new concerns about terrorist attacks by sea, the fight against the SPSS vessels off Colombia could have implications for America’s ­security. Nobody expects a Colombian drug lord to launch an attack with wea­pons of mass destruction, but the SPSS technology might be used by enemies who would.

THE SOURCE: “A New Underwater Threat” by Wade F. Wilkenson, in Proceedings, Oct. 2008.

Photo courtesy of The U.S. Navy