In the damp December cold, a blue bus stops near Weymouth town centre in southwest England. A few men get off, relieved to be spending a few hours away from what they call their "prison" -- a barge housing asylum seekers.

Hasan James, a 38-year-old Nigerian, is one of around 200 migrants staying on the Bibby Stockholm in the port of Portland, around 20 minutes' drive from Weymouth on the Dorset coast.

"We have limited mobility. It is just like prison security," James, wrapped in a warm parka jacket and hat, said of the controversial accommodation, detailing its detection scanners and searches.

Before the UK authorities sent him to the facility a month ago, James, who arrived in Britain on a now-expired tourist visa, was living in a hotel in London.

"Not everything is awful on board," he said, pointing out that he liked the food, but he said he found the feeling of isolation "really challenging".

"It makes me feel like I'm in a different world," he told AFP.

Migrant charities have questioned living conditions on the vessel.

One migrant on the barge used a translation app on his phone to tell AFP: "Everything is very bad there. They don't treat us like humans."

Britain is currently seeing record numbers of migrants arriving on its southern coast by small boats from northern France.

Almost 30,000 people have arrived so far this year.

More than 110,000 migrants have made the sea crossing since Britain began publicly recording the arrivals in 2018.

To reduce the cost of housing them in hotels while their asylum applications are assessed, and to discourage new arrivals, the government announced in April that it would put around 500 asylum seekers on the barge.

The first arrived in August but had to leave a few days later following the discovery of Legionella bacteria in the water supply.

They began returning in mid-October.

Earlier this month, an asylum seeker on board died.

- 'Fresh air' -

Lodman, a 50-year-old Iranian, arrived two weeks ago. He also struggles with his limited freedom.

"It's really bad, like a prison. It's depressing," he says.

A 22-year-old Iraqi man, who arrived illegally by boat from France and who did not want to give his name for fear of harming his asylum application, said he disliked the lack of privacy.

He showed a video of the room, just a few square metres (square yards) in size, that he shares with another person, and said guards show indifference when some residents complain.

"They don't care," he explained, dragging frantically on a cigarette.

Activities do take place on board, including a gym, but "there are too many people", the young man lamented.

Many of the men head to Weymouth whenever they can, sometimes several times a week.

A special bus service takes them there, the last one returning to the barge late at night.

In the seaside town, they buy a Coca-Cola with their weekly allowance of £9.58 ($12) and mill about.

"(We come) just to walk and for the fresh air," said the Iraqi.

The idle men do not go unnoticed by passers-by finishing up their Christmas shopping.

"There are not a lot of black people here," said James, "so people here know we come from the barge".

"Some wave at us. Some have been saying 'Merry Christmas'. They are welcoming," he smiled.

The Iraqi noticed that some local residents look at him.

"'Oh he's a refugee'," he hears them say. "It is not racist but..," added the migrant.

- Mental issues -

Some residents of Portland, a small town of 13,000 inhabitants, expressed anger when the government announced its plans for the barge, which has continued to attract controversy.

Earlier this month, an asylum seeker on the Bibby Stockholm died.

Authorities are investigating the cause of death, but charities said it was suicide and have questioned living conditions there.

In front of the barriers that prevent access to the port, flowers and messages left in tribute to the man -- a 27-year-old Albanian, according to British media -- remain.

"We missed the chance to get to know you, but we will fight to end inhumanity," reads one tribute.

James did not know the man but said some residents were starting to "fight mental issues".

No asylum seeker knows when he will leave the barge.

"(But) we are praying that it will soon be over," said James, bringing with it the right to remain the United Kingdom.