Two years ago, Arsenio's brother and 1,540 pounds of cocaine disappeared on the way to Panama in a small speedboat.
After his brother's death, Arsenio (who spoke on condition that his real name not be used) could have cut all ties with Colombia's lucrative cocaine and heroin trade.
Today, on the deck of a restaurant overlooking the black waters of Tumaco Bay, the mechanic and small-time marijuana dealer glances nervously over his shoulder before admitting that he chose not to.
"Of course it's dangerous," says Arsenio, who now works fine-tuning high-powered "go-fast" speedboat motors for smugglers. "You're on the open sea with four-meter [12-foot] waves.
"But people from the coast are used to the sea breeze," he says. "You have to die sometime. And for that much money, it's worth the risk."
Go-fast pilots like Arsenio's brother are becoming an increasingly vital piece of Colombia's drug trade and one law enforcement officials are having a particularly hard time combatting. The boats' fiberglass hulls barely register on a radar screen. Painted a dull blue, they are almost impossible to spot with the naked eye especially amid the drizzle off the Pacific coast, one of the wettest spots on earth.
Easily concealed along Colombia's 1,700 miles of swampy coastland, the boats leave the country today at the rate of more than a dozen per month each carrying at least two tons of cocaine and heroin.
"You can be in a customs launch, and the boat you're waiting to intercept can pass you 50 meters [150 feet] away," complains Naval Intelligence officer Capt. Fernando Torres. "You can hear it, but you don't see a thing."
Pacific coast smugglers head for the beaches of Panama and Costa Rica, or strike out westwards to the Galápagos Islands, where they pass drugs on to cargo freighters. From Colombia's Northern coast, go-fasts aim for Caribbean islands.
Depending on their drugs' destination, smugglers dump them on an isolated beach, hand them over to local fishermen, or leave them floating at sea for a later pickup. The contraband is then shipped to the US mainland in freight containers, or carried on small planes or commercial airline flights.
For longer trips, Global Positioning Systems devices enable smugglers to rendezvous with fishing boats fitted with extra gas tanks; some boats can make it all the way to Mexico.
But even with sophisticated navigation and communication systems, crossing the ocean in a 30-foot open boat is a dangerous and potentially deadly undertaking.
"Hours at sea, with no points of reference, and no back-up. [Go-fast pilots] are real experts," says Captain Esaud Becerra, head of intelligence at the Tumaco naval base. "They have no formal training, but they never get lost. Sometimes you have to admire them."
The hazards are enormous, but so are the pay-offs: According to police sources, a go-fast pilot can earn up to $10,000 on a long voyage. In this town of ramshackle houses, it is easy to imagine why a boatman might swap shrimp fishing for drug running.
In addition, over the past three years, an illegal paramilitary army known as the United Self-Defense Groups of Colombia (AUC) has taken control of this part of the country's Pacific coast, forming lucrative protection deals with smugglers.
US and Colombian officials say there is also evidence that paramilitary groups are directly involved in go-fast shipping. In July, the Colombian navy destroyed an AUC-operated cocaine laboratory and captured five boats north of the Mejicano River.
Despite the dangers, smugglers have a few advantages. Once a go-fast reaches the open sea, it is almost impossible to detect. When authorities do spot a boat, they're hard-pressed to catch it. Fitted with up to five 250-horsepower outboard motors, go-fasts can reach speeds of 50 knots (about 60 mph) faster than most Navy vessels.
Authorities have had some success catching the smugglers, thanks largely to tip-offs and wiretaps. This year the Colombian navy has caught 11 go-fasts carrying almost nine tons of cocaine. The latest, in May, held 2.25 tons.
But smugglers are constantly developing new techniques. According to Arsenio, drug cartels are already at work on new generation of go-fasts with hi-tech turbines that let them skim over the water at more than 60 mph.
Though the Colombian navy is working on an "anti-go-fast" boat designed to pursue traffickers on the open sea, critics are skeptical that officials will ever keep pace with smugglers. Two years ago, police discovered a half-completed 75-foot submarine that they believe was designed to carry up to 10 tons of drugs.
"The drug smugglers make so much money, they are going to be on the cutting edge of technology," says one US official involved in antidrug efforts. "Whatever's the biggest and the fastest, they're going to have it before we do."