In the chilly, rough waters of the Aegean Sea, tricky under the best of circumstances and downright treacherous in a flimsy migrant boat, a life vest can make the difference between life and death.

But for the unlucky refugees who would have bought roughly 1,200 life vests being manufactured in Izmir, Turkey, that was a false promise.

The vests were fake, according to Associated Press, citing Turkish reports. They were made of a material that becomes heavy when soaked and would have caused their wearers to sink.

Turkish police raided the workshop in Izmir — a port city that is often a departure point for migrants hoping to make it to Europe — and found workers stuffing the jackets with packaging rather than buoyancy aids, according to the BBC.

Of the four workers, two were young Syrian girls, the BBC said.

More than 1 million migrants traversed the Mediterranean last year, most of them from Syria and most traveling from Turkey to Greece. The sea voyage is just one step of a perilous journey.

According to Hurriyet, a Turkish daily, Syrians tend to congregate in Izmir while they seek passage on a smuggling boat — and the funds to pay for it. They stay in cheap hotels or else on the street. They take work if they can find it. They eat what they can, if they can. They wait for a smuggler’s phone call that often comes in the middle of the night: “We’re leaving now.”

Because smugglers don’t generally provide life jackets, migrants must acquire them on their own. A properly made jacket costs up to $150, according to the BBC. An improperly made jacket may be as little as $15 but has almost no hope of floating. Many migrants, strapped for cash but desperate for some semblance of protection, will still buy them.

These under-the-counter vests are often black, according to Hurriyet — the better for avoiding the attention of authorities at sea.

On Thursday, police in Izmir also collected about 300 substandard vests from Syrian migrants who had already purchased them, Hurriyet reported.

Sait Güderoğlu, one of Turkey’s top life vest producers, told the newspaper that these fake life vests can endanger wearers even more than no vest at all.

“Such life jackets are made of backpack material and filled with sponge and because sponge is hydrophilic [water absorbing], it drags people down and causes them to drown,” he said.

More than 3,700 people died attempting to cross the Mediterranean during 2015, the International Organization for Migration reported this week. It was the deadliest year on record for migrants and refugees in the region.

And just this week, the bodies of more than 30 people washed ashore in Turkey after their boats capsized in rough water while trying to reach the Greek island of Lesbos, according to the Associated Press. Some of the drowned migrants were children.

Images from the terrible scene show that many of the migrants, including the kids, still wore the life vests that had apparently been of no use to them.