Ali sat shivering and exhausted on a pebble beach on England's south coast but thankful for a "new life" after he and 30 other migrants were rescued in the Channel.

The Syrian asylum seeker, from the eastern city of Deir Ezzor, said he had been stranded in the sea between England and France for 12 hours on an inflatable boat before he and the others, including several children, were plucked to safety.

Ali, 22, who gave only his first name, was brought ashore on Wednesday. On the other side of the busy Channel, 27 fellow migrants were not so lucky.

Lifeboat crews in Dungeness, on the south coast of England, are regularly involved in rescuing migrants in the Channel Lifeboat crews in Dungeness, on the south coast of England, are regularly involved in rescuing migrants in the Channel Photo: AFP / Ben STANSALL

Men, women and children perished in the freezing winter water when their boat capsized, in the deadliest accident in the Channel since UN migration records began in 2014.

Ali and the others could have suffered the same fate: they had to use plastic bottles to bail out water that threatened to sink their own vessel beneath the waves.

"We were scared because we didn't know what would happen with us," he told AFP moments after he disembarked a rescue vessel near Dungeness lifeboat station in Kent.

"We were in the middle of the sea. There were children in the boat. Of course we were worried for them, worried for everybody."

The British authorities have linked the increase in arrivals to the use of larger inflatable boats than in previous years The British authorities have linked the increase in arrivals to the use of larger inflatable boats than in previous years Photo: AFP / Ben STANSALL

Ali's story is an increasingly familiar one of exploitation and desperation that has seen urgent calls for a crackdown on those trading in human misery.

He paid a people smuggler in France ?2,000 ($2,664, 2,375 euros) for a place on a large rubber dinghy. For some, the cost is even higher.

Migrant crossings by boat to England have risen to record highs this year, even beyond the warmer summer months.

Wednesday's tragedy, in which 27 men, women and children died trying to reach Britain from northern France, did not deter others from making the crossing Wednesday's tragedy, in which 27 men, women and children died trying to reach Britain from northern France, did not deter others from making the crossing Photo: AFP / Ben STANSALL

The British authorities have linked the increase in arrivals to the use of larger inflatable boats than in previous years.

Wednesday's tragedy, involving mostly Iraqi Kurds, Iranians and Afghans, according to those that met them in northern France in recent days, did little to deter others from attempting the same crossing.

Desperate migrants have paid thousands of euros (dollars, pounds) to criminal gangs to ensure a place on the small boats that are ill-equipped to make the journey, particularly in bad weather Desperate migrants have paid thousands of euros (dollars, pounds) to criminal gangs to ensure a place on the small boats that are ill-equipped to make the journey, particularly in bad weather Photo: AFP / Ben STANSALL

In Calais, Emmanuel D'Mulbah said his heart was broken by the deaths but shrugged his shoulders and said he would attempt the journey when the sea was calmer.

Earlier this week, French police stopped him and 23 others before they could put to sea.

"It's my dream," said D'Mulbah, from Liberia. "It's daunting. I'm scared. But I'll keep going."

In Dover, some 33 kilometres (20 miles) across the Channel, other migrants successfully crossed the maritime border and were brought in from the early hours of Thursday.

They were put on a red double-decker bus at the port to be taken for processing.

Along the coast in Dungeness, adults and small children were given blankets to wrap themselves in. The temperature was just 5 degrees Celsius (41 degrees Fahrenheit) on land, and even colder out at sea.

Mounir Khan from Kabul, was processed at the volunteer lifeboat station on the headland before he boarded a UK Border Force coach with his two teenage sons.

If they had not been rescued by the lifeboat, he said, all 30 making the perilous trip from northern France would have lost their lives.

Khan, 45, fled his homeland a little over a month ago, fearing reprisal attacks from the Taliban following the withdrawal of US-led NATO forces.

He and his brother were targets, he said, as they had worked with the Afghan military.

"The Taliban would take people in the night and kill you and nobody would (know) where you'd gone," he added.

The sea crossing, past giant tankers and car ferries in the world's busiest shipping lane, was Khan's first time on open water.

The experience left him scared and shaken -- and grateful to the lifeboat crew, when their vessel hove into view.

"There was water in the boat and the air is gone," he said as the large punctured black dinghy he arrived on was towed up the stony beach, with water still in its stern.

"All the people would have died. They (the lifeboat crew) saved all these people's lives."