“This will be a hot pursuit tonight,” the coast guard captain tells me.

It is dusk over Tripoli’s harbor and we are standing in the control room of the Kifah, an aging, German-made patrol boat. I had joined its crew of eighteen one evening last month expecting to be searching for migrants at sea. But like so much in Libya, the plan changed.

Earlier that day, the coast guard had been tipped off that a fuel smuggling tanker was departing from Zuwara, a town some 113 kilometers west of Tripoli. The Kifah is heading to intercept it, hopefully by dawn the next day if the captain has correctly guessed its heading and speed.

Gasoline is cheaper than water in Libya, which has the largest oil reserves in Africa and currently pumps just over 800,000 barrels per day. The smuggling of refined products has become a multi-billion dollar enterprise, run by networks throughout the country with links to cartels, brokers, and buyers across the Mediterranean. A liter of diesel that costs 0.15 dinars (around 10 cents) in Libya sells for nearly five times that amount on foreign markets. With fuel subsidies representing over 10 percent of the Libyan GDP, smuggling is a serious drain on the economy; Libya is estimated to have lost half a billion dollars because of it. And the web of corruption is vast, snaring everyone from gas station owners and small car drivers to militias and parts of the government itself.

“This is a bleeding of the Libyan body,” the captain says, slicing his wrist with a finger for effect.

A 31-year veteran of the navy and coast guard, he wonders why the Europeans are so focused on stopping migrants and not fuel smugglers. It is the latter, he says, who are harming Libya more, sustaining its chaos and violence. It has affected him personally, he adds. Six months ago, smugglers briefly kidnapped his eighteen-year old son, as a warning.

Smuggling in western Libya often starts at the refinery of Zawiya, 40 kilometers west of Tripoli. Products are taken across the Tunisian border by truck or hidden in cars. Tunis’ recent border fortifications, which include berms and moats, have failed to stop the trafficking. Seaborne smugglers depart from the nearby port of Zuwara. The local coast guard and the Petroleum Facilities Guard are complicit in providing protection.

The smugglers’ ships hold millions of liters, so the financial stakes are enormous. Their crews fight coast guard vessels, with a phalanx of smaller boats armed with heavy caliber weapons surrounding tankers. The Kifah fought a three-hour battle with some of them a week before I came aboard.

Just before dawn, about 48 kilometers off the coast, the captain spots a darkened vessel on the gauzy horizon. It does not respond to radio calls, so the crew clambers to the guns on the bow and stern. “Use the spotlight,” yells one of them. It is a trawler, the type sometimes used to transfer smuggled fuel to a larger craft waiting in international waters.

A voice finally crackles on the radio, speaking in an Egyptian accent. It is a fishing boat, the crewmember declares, Egyptian-flagged but sailing from Zuwara. The captain is suspicious. Illegal fishing is another scourge that Libya is facing, with boats coming from across the Mediterranean to snatch bluefin tuna and other bounty from its waters.

The captain asks for his permit or to speak with his Libyan escort, which is required by regulations. The Egyptian knows the game is up.

“You animal,” the captain growls, “pull up your nets or I’ll take you out.”

This is not the first time the captain has dispensed with maritime etiquette.

The day before, the Kifah sped dangerously close to a vessel operated by the Sea Watch nongovernmental organization, which was trying to recover migrants from a wooden boat and distributing lifejackets to them. The Libyan captain maintains that as a warship he had the right of “on-scene command” and that a Sea Watch boat was trying to cut him off to prevent him from taking the migrants. But released video clearly shows a dangerous maneuver, corroborated by the eyewitness account of a Sea Watch crewperson with whom I spoke. She asserted that since the migrants’ boat had left Libyan territorial waters, the captain had no legal basis to take them back to inhumane and violence-plagued detention centers ashore.

The episode was one of several instances—including shooting at migrant craft and beating migrants with hoses—that highlight recurring abuses by the Libyan coast guard, a force that European Union countries are training and equipping in an effort to stem the migrant surge.

As the morning unfolds, we see no sign of a fuel tanker. “Maybe they turned back or they’re still at port,” the captain offers. He steers us south and then southeast, heading home. A lookout scans for boats of migrants off the coast of Sabratha, a town that is now a major point of departure.

It strikes me that the patrol is a Sisyphean exercise. Given the sophistication of the smuggling enterprise, the vastness of the sea, and the meager capability of the coast guard, it is akin to throwing darts at balloons in a dark room. The captain agrees, cursing his commercial grade radar, which he says is outmatched by those of the smugglers.

Yet a lasting solution to Libya’s hemorrhaging sovereignty won’t be found at sea, through a better-equipped, better-trained coast guard. Rather, it lies on land, through the far more difficult task of undoing decades of institutionalized corruption and the pathologies of an oil-based economy. A few of Libya’s more progressive-minded leaders have realized this, but whether they can implement it is another story.

The skyline of Tripoli comes into view, blurred by a sandstorm. A few dolphins leap in our wake and the crew test-fire their guns into the air. We never find any migrant craft that day, only the remnant of an aborted crossing: a drifting, deflated dinghy, half-submerged by the motor weighing it down.