The vacation had been everything that Angelique and Onno Bos dreamed it would be.

With their four children, the Dutch couple had taken full advantage of the first-class amenities on the picture-perfect Greek island of Lesbos: They power-boated through aqua-green waves, scootered along breathtaking mountain passes and whiled away the days on secluded sandy beaches.

At 10 p.m. the night before their flight back to Holland, they did something impulsive and uncharacteristic: They cancelled their trip home – not to extend their idyll, but to provide aid to some of the thousands of refugees who, like the tourists, have been drawn to Lesbos this summer.

“We’d seen refugees all over the island, walking along the roads. And we kept saying to each other: What can we do to help?” said Angelique Bos, 47.

As an extraordinary tide of migrants has washed up on the island’s shores in recent months from across the sea in Turkey, local authorities are overwhelmed, the nearly bankrupt Greek government is unable to help and the European Union is nowhere to be seen. The result is that the migrants, the vast majority of them fleeing war and persecution, spend their first days and nights in the EU living in squalor, with little access to food, water or medicine.

International aid organisations have stepped into the breach. But so, too, have Lesbos residents, as well as some of the well-heeled European tourists who came here for the sun but who unexpectedly found themselves drawn to help.

For Angelique Bos, help meant handing out cookies, water and hugs one recent day to dozens of migrants minutes after their flimsy rubber raft was picked up by the Greek Coast Guard and towed into shore. The migrants – a cross-section from the world’s conflict zones – thanked her repeatedly. Ms Bos said she was the one feeling grateful.

“It’s been the best vacation ever,” she said. “We’ve been helping for 12 days now, and we’ll stay five more. Then we’ll have to stop.”

But that won’t be the end of their efforts. Back in Holland, they intend to raise money to buy a car to ferry the migrants across the island and to pay for housing for future volunteers.

“I always felt sorry for the refugees when I saw them on television,” Ms Bos said. “But now it’s different. We’ve met them.”

Melinda McRostie, who has lived on the island for 45 years and coordinates relief efforts from the kitchen of her family’s restaurant at the island’s northwestern tip, said the tourists have played an indispensable role in her all-volunteer campaign.

“The fridge broke down the other day. Someone stepped in and bought me a new one,” she said as she prepared the night’s dinner offerings and juggled calls on multiple phones reporting new arrivals and migrants in distress. “It’s been amazing how many people want to help.”

Not everyone, of course, is so eager to lend a hand. Several doors down from Ms McRostie’s restaurant along this village’s quaint cobblestone seafront, another restaurant owner complained that the presence of the migrants had been terrible for his business.

“I’m very sorry for them. But I’m also sorry for my own family,” said the owner, who only gave his first name, Michalis. “I know there is war where there they come from, but what about us? We’ve got a financial crisis here in Greece.”

The presence of the migrants may be putting off some tourists. But for others, it’s all the more reason to keep coming back.

Laura Ferris and Pete Oldroyd, a couple in their mid-50s from Yorkshire, walked out of their hotel at dawn one recent morning and found dozens of migrants sleeping in the street. They had come in on a boat only hours before and were exhausted from the treacherous journey.

Throughout the morning, Ms Ferris and Oldroyd handed out food and water, and entertained the children while their parents rested. Mr Oldroyd lent the kids his binoculars. “Take a look!” he said, as the children peered out at an ancient stone castle, one of the top local attractions.

When the couple first heard about the migrant crisis gripping their intended holiday destination, they weren’t sure what to think. The plan had been to lie on the beach and soak up the rays they don’t get enough of in England.

In pictures: Calais crisis Show all 15 1 /15 In pictures: Calais crisis In pictures: Calais crisis Calais crisis Migrants climb in the back of a lorry on the A16 highway leading to the Eurotunnel in Calais Getty Images In pictures: Calais crisis Calais crisis Protesting French employees of the company English Channel passenger and freight ferry company "MyFerryLink" block the railway tracks of the Eurostar Channel tunnel line in Calais Getty Images In pictures: Calais crisis Calais crisis Protesting French employees of the company English Channel passenger and freight ferry company "MyFerryLink" block the railway tracks of the Eurostar Channel tunnel line with a burning plastic barrier In pictures: Calais crisis Calais crisis French riot police officers drive out protesting French employees of the freight ferry company MyFerryLink Getty Images In pictures: Calais crisis Calais crisis French riot police take position to drive out protesters blocking the railway tracks Getty Images In pictures: Calais crisis Calais crisis Passengers stranded by the cancellation of Eurostar trains wait at St. Pancras station in London. Eurostar said it has canceled all passenger trains through the tunnel that links France and England, after striking ferry workers swarmed the train line setting tires alight In pictures: Calais crisis Calais crisis Passengers sit on stairs after being stranded by cancelled Eurostar trains at St. Pancras station in London In pictures: Calais crisis Calais crisis A police vehicle drives past lorries are backed up on the M20 motorway which leads from London to the Channel Tunnel terminal at Ashford and the Ferry Terminal at Dover In pictures: Calais crisis Calais crisis Trucks queue up as part of Operation Stack in Dover In pictures: Calais crisis Calais crisis Cars queue to board a ferry in Dover bound for Dunkirk, France, as the disruption at Calais looks set to enter a second day as migrants continue to target lorries in a bid to cross into the UK In pictures: Calais crisis Calais crisis A police officer sprays tear gas to migrants trying to access the Channel Tunnel on the A16 highway in Calais, northern France PHILIPPE HUGUEN/AFP/Getty Images In pictures: Calais crisis Calais crisis Migrants wait near the A16 highway as they try to access the Channel Tunnel in Calais, northern France PHILIPPE HUGUEN/AFP/Getty Images In pictures: Calais crisis Calais crisis Striking employees of the French company My Ferry Link, a cross-channel ferry service, stand in front of tyres set on fire as they block the access to the Channel Tunnel in Calais, northern France PHILIPPE HUGUEN/AFP/Getty Images In pictures: Calais crisis Calais crisis A striking employee of the French company My Ferry Link, a cross-channel ferry service, sits on a tyre in front of tyres set on fire as he takes part in a blockade of the access to the Channel Tunnel in Calais, northern France PHILIPPE HUGUEN/AFP/Getty Images In pictures: Calais crisis Calais crisis Striking employees of the French company My Ferry Link, a cross-channel ferry service, prepare to set tyres on fire to block the access to the Channel Tunnel in Calais, northern France PHILIPPE HUGUEN/AFP/Getty Images

But the plan soon changed. When they boarded their flight, they came prepared with extra suitcases packed full of donations.

“I have no T-shirts when I get home because Laura gave them all away,” said Mr Oldroyd, a logistics manager.

Instead of hanging out on the beach, they picked up trash from a migrant camp that even veteran international aid workers say is abysmally managed. “It’s the most humbling thing I’ve ever seen in my life,” Mr Oldroyd said as he choked back tears.

When it came time for the migrants who had landed that morning to board a bus to take them to the camp, everyone was crying: the children and their parents, the tourists and the local volunteers.

“These people have come through so much to get here, and this is only half their journey,” said Ms Ferris, who intends to return with Mr Oldroyd in September. “It breaks your heart.”