Colombia's drug barons used to favour high-speed powerboats to export their deadly cargos, leading law enforcers on high-speed chases as they swamped America with narcotics.
Now, in an attempt to evade American surveillance, they are diverting their smuggling trade beneath the waves. Coast Guard and military patrols have reported a dramatic increase in do-it-yourself "semi-submersible" vessels that evade radar and sonar, barely breaking the ocean surface as they creep through the Pacific or the Caribbean..
According to new figures from the US Department of Homeland Security, such slow but stealthy voyages now account for 32 per cent of all maritime cocaine traffic between Latin America and the US. The American Coast Guard reported just 23 incidents involving submarines between 2000 and 2007, but 62 in the first nine months of this year alone.
Each craft can carry anything up to 10 tons of cocaine, with a wholesale value of more than $250 million. But even though their maximum speed is usually no more than 13 knots, tracking them down is a challenge.
"The ocean out there is so vast that looking for one of these things is like finding a needle in a haystack - in fact, it would probably be easier to find a needle in a haystack," admitted Michael Sanders of the Drug Enforcement Administration.
"When we first started seeing them years ago they were kind of crude and home-built, but now they've become more sophisticated. These guys are starting to learn."
In their attempts to detect and intercept the narco-subs, US Coast Guard and military squads are forced into sometimes death-defying situations. In one incident 350 miles off Guatemala last month, a Coast Guard boarding party climbed atop a submarine, only for the crew down below to suddenly thrust the engines into reverse in an attempt to throw them off, leaving them clinging for life to the exhaust pipes. Then the crew opened the scuttling valves to try to sink the vessel and attempted to escape through the conning tower, before they were overpowered.
"Our guys were up to their necks in water, it was an extraordinarily dangerous situation," said Lieutenant Commander Chris O'Neil of the US Coast Guard.
"The operators of these vessels are directed (by their paymasters) to scuttle them in the event of discovery. Water rushes in, they can sink these things in minutes if not seconds. This stuff sinks to the bottom of the ocean, hundreds of millions of dollars worth, and we're left with no evidence to prosecute."
Congress therefore passed legislation in July, now awaiting the president's signature, that will make it easier to prosecute crews even without the drugs being recovered. Law enforcers hope to use it as leverage to elicit information from captured crews that will lead them to the trafficking kingpins back in Colombia.
The so-called narco-subs are built next to river estuaries in the jungles of Colombia and launched mainly from the country's Pacific coast, considered a smuggler's paradise for its secretive coves and miles of thick forest.
Their hulls - usually under 100ft in length - used to be made from wood but now steel is the material of choice, topped off by fibreglass. Many are fitted with elaborate navigation equipment, radio communications and diesel engines that allow them to travel over 2,500 miles without refuelling.
Construction can take a year and cost up to $1 million, with crews having to haul materials and equipment such as generators into the jungle and sleep in mosquito-infested camps.
The vessels are classed as "semi-submersibles" because of their inability to dive and their reliance on snorkels that protrude just above the waves to provide air for the engines and crew. Of those that have been intercepted by anti-smuggling patrols, some travel with three inches of their structure above the waterline, while others are capable of going as much as 15ft below the surface.
"Inside, they're pretty bare-bones affairs. There's no comfort, no amenities. They are deathtraps," said Mr Sanders. He said that while drug tycoons did not put out "press releases" on the numbers lost, he estimated that anything up to 50 per cent ended up being sunk or scuttled for one reason or other.
The traffickers have also forged alliances with drug gangs in Mexico, which take delivery of cocaine shipments off their own country's coast, take it ashore and then across land borders into America.
In the 1970s, the smugglers used to get their hauls into the US in hand-delivered briefcases or dropped from aircraft. When law enforcers began to catch up with them, they took to speedboats, fishing vessels and cargo containers.
"It's a reflection of how successful we have been in detecting their other means of transports that now we have the semi-submersibles. They have been forced to these extreme measures," said Lt Cdr O'Neil.
# Jacqui Goddard
# Telegraph Online
# October 19, 2008