In the dead of night, a Greek coast guard patrol boat slips its moorings, heading out across the bay toward the Aegean Sea that separates the island of Lesvos from the nearby Turkish coast.

As the boat picks up speed, a crew member scours the dark sea, looking at a night-vision camera monitor. It doesn't take long to find what he's looking for.

Barely out of port of the island's capital, Mytilene, he spots a small but unmistakable black shape: an inflatable dinghy crammed with dozens of migrants, heading straight toward the coast.

"Stop the boat! Stop the boat and turn off your engines! This is the Hellenic Coast Guard," the crew tells the dinghy through a loudspeaker as its powerful searchlight illuminates the fluorescent strips on the passengers' life jackets.

But the dinghy, already near a beach beneath a nightclub on a hill, pays it no heed. In just a few short minutes, its passengers have arrived and leap out, splashing through the water. The migrants quickly ditch their lifejackets, gather their few belongings and climb up a brief incline onto the road above.

It's a scene repeated several times a night, every night and sometimes even during the day, all along Lesvos' long coastline facing Turkey. The island, the third largest in Greece, has become the main point of entry into the country for thousands of refugees and migrants heading into the European Union, fleeing war and poverty back home.

More than 25,000 people have reached the island so far this year — a 620 percent increase from the same period last year, says Lesvos Coast Guard Lt. Commander Antonios Sofiadelis, who is also the local coordinator of a joint European operation by Frontex, Europe's border agency.

Greece is reeling from massive numbers of refugees and migrants arriving on the shores of its eastern Aegean islands, with numbers already surpassing 55,000 this year.

"(They) arrive daily, mainly in inflatable dinghies of dubious seaworthiness, small engines, 30 to 40 people on board, many times without lifejackets, without safety equipment, without navigation lights, sometimes under difficult weather conditions," Sofiadelis said.

He said his crews have carried out search-and-rescue missions for more than 300 of the roughly 500 smugglers' vessels reaching the island's shores.

Many also reach the coast out of sight of the patrols. The vast majority are refugees from Syria, Iraq and Afghanistan, many with young children and infants in tow.

"It's very difficult, very dangerous," said Hussain Amer, a 26-year-old Syrian who arrived at dawn recently on a rocky beach near the island's airport. "It's very hard. We had many children, about 10 of them ... we came because of the war. In Syria, it's very dangerous."

Amer said it took him about seven days to reach Greece from Syria, using a combination of buses and walking through Turkey.

Another man named Abdullah, also from Syria, arrived on a separate boat three days later.

"We are looking for better life, a safe life," said Abdullah, who would only give his first name. "Especially a safe life for the children."