The hottest commodity in the saga of migrants risking death to reach European shores: decrepit wooden fishing boats. And Italy is asking the United States to supply drones that can identify them before they're packed with refugees and sent across the Mediterranean.

Anticipating every European move, however, the nimble smugglers are turning now to a newer, cheaper and more dangerous tactic — launching rubber dinghies crammed with migrants that sometimes start deflating even before they reach Italy.

The twin tactics point to the challenges European leaders face in cracking down on the traffickers' most important tool: the boats that carry the migrants across from Libya. Seizing or even sinking these vessels before they are packed with migrants and sent across the Mediterranean could substantially dent a multi-million dollar trade. But the smugglers are constantly coming up with innovative ways to thwart potential clampdowns.

The latest smuggling tactic is inflatable rubber dinghies.

Measuring 12 meters (40 feet), the boats aren't supposed to hold more than 20 people. But rescuers increasingly find them foundering at sea with more than 100 aboard — and believe many sink unnoticed, adding untold victims to the 1,700 counted dead or missing on the journey so far this year.

The troubling new trend of inflatable dinghies powered by outboard motors may be impossible to stop. Stored deflated, they are hard to spot even by drones. And it doesn't take long under cover of darkness to inflate them on Libya's long stretches of deserted beaches for loading with migrants.

Intelligence supplied to Frontex — the European Union's border patrol mission — indicates that the dinghies have been manufactured in China and Taiwan. But authorities don't know how they are making it into Libya. Even if they did, halting dinghy shipments to paying Libya customers would be difficult to enforce, said Mark Shaw, director of the Geneva-based Global Initiative Against Transnational Organized Crime.

"Libya is a smuggler's paradise and the inflatable boats fit the bill for a cheap, disposable craft," said Shaw, also a criminology professor at South Africa's University of Cape Town. "For people on the inflatable boat side of it, it's a no-brainer to move them in there. To bring in a container of them in would not be particularly hard."

The wooden fishing boats remain a prized transport method because they can hold many more migrants than rubber boats, even if by normal standards they are barely seaworthy.

Libyan smugglers value the boats so highly that they are now dispatching speedboats to recover them after the migrants on board are saved by the ships working for Frontex.

Italy's defense minister wants U.S. help with drones to identify the ships while they're still empty in Libyan ports. And Spain's ruling Popular Party says sinking them before they depart could be an option. Lawless Libya, which has no functioning central government, is the main departure port across the Mediterranean for Syrians, Eritreans and a host of others trying to make it to Europe.

Tunisia — a main launching point for migrants a few years ago — is a key supplier of wooden boats to Libya's smugglers, according to Frontex.

Frontex said it does not know how the smugglers get the Tunisian boats. And people involved in the smuggling interviewed after arriving in Italy have not provided details, said Antonino Ciavola, chief of the police rapid response team in Ragusa, Sicily, a base for many migrant rescues.

But it makes sense that the smugglers would seek them because of convenience and proximity, according to Matthew Herbert, a Tunisia expert with the Strategic Capacity Group, a nonprofit security research group based in the U.S. state of Virginia.

"They're not procuring boats from Tunisia because they like Tunisian boats," Herbert said. "They are procuring them because they are probably the easiest and cheapest to get at the moment, and boats are among the most easily movable commodities in the world. You simply move them on the water."

The smugglers have traditionally sent the larger boats on one-way trips toward Italy, appointing one migrant as a captain after giving him rudimentary training and a satellite phone to call rescuers. Now twice this year, traffickers have sent speedboats with armed men aboard from Libya to trail the migrant boats at a distance.

In the most recent incident documented by Frontex, an Icelandic Coast Guard vessel with 342 rescued migrants aboard was called by an Italian tugboat to help rescue another 250 migrants from another boat. Just after they were saved, a speedboat with armed men firing shots into the air turned up and took away the empty migrant vessel, Frontex said in a statement.

The incident and another similar one this year were the first of their kind known to Frontex. They were "a sign that smugglers in Libya are running short of boats and are more willing to use weapons to recover those used to transport the migrants," said Frontex Executive Director Fabrice Leggeri.

The larger boats cause bigger numbers of migrant deaths when they capsize or sink, but Ciavola said it's more perilous for migrants to make the trip on the smaller inflatable boats. In the most dramatic recent case of dinghy overloading, rescuers saved 118 people loaded onto an inflatable boat made for 20.

"These rubber boats are much more dangerous than the wooden boats," he said. "With the wooden boats, unfortunately, many people die all at once. With the rubber boats, many people are dying every day."


Gera reported from Warsaw. Associated Press writer Colleen Barry contributed from Milan, Italy.