Mercy ships are staffed by volunteers and have been stocked with state-of-the-art equipment

Today they are regarded as great ­pioneers in the field of “frontline” medical aid and earlier this week in London Don and Deyon were presented with the Humanitarian Award from Variety, the international children’s charity, for their dedication over the past 30 years of taking the best medical care the First World has to offer to the poorest people of the Third World.

But when they started out it was a different story. The most common ­reaction to their project was extreme scepticism, if not disdain.

Yesterday Don recalled: “We’d go to see all these men in striped suits at the bank and they would listen very politely and then say: ‘So let me get this straight: you’re not a professional mariner and you’ve never run a hospital but you want me to lend you a million dollars to buy a ship?' ”

The idea had taken root in Don’s mind during a church trip to the ­Bahamas in 1964 when he was 19 and Deyon 18

. “There was a hurricane and I heard that one of the girls had prayed for a ship to come with everything that was needed to clear up the storm damage,” said Don.

“I didn’t hear the prayer myself but it was like a laser beam going off. I couldn’t get the idea out of my mind and I knew it was what I wanted to do.”

The American couple married two years later and continued their education; Don graduated in theology and Deyon trained as a nurse.

They also came to Europe to start a family. Their dream of founding a floating hospital never faded and indeed was strengthened by two events.

First, their third child John Paul, now 33, was born with learning difficulties. In the same year, 1976, Don met Mother Teresa at one of her homes for the handicapped in Calcutta.

“She was only with me 10 or 15 minutes but in that time I had told her about our special-needs son and our dream of a hospital ship and she said: ‘John Paul will help you to become the eyes and ears and limbs for many ­others.' ”

After numerous refusals Don and Deyon eventually found a Swiss bank that was willing to lend them money for the ship. ­­

“Twenty years later we found out the bank had only done so because a Swiss family which own a large commodities trading firm had heard about our idea and put in a ­quiet word with the bank. Basically they promised to guarantee the loan.”

An old-established London shipping company helped them find a vessel and Brian ­Batten, the principal surveyor of passenger ships for Lloyds, made sure she was ­seaworthy.

In 1980, Don and Deyon decided to go and live on the Anastasis with their four children – a daughter and three boys – who were then all aged under 11.

They stayed for 10 years and the children were educated in the on-board school for the families of ­permanent crew.

T he Anastasis was joined by two more ships, the Caribbean Mercy and the Island Mercy, which have travelled to 12 countries in Africa, four in Latin America and 12 in Asia.

All three ships have been sold in recent years to be replaced by the Africa Mercy which was fitted out at the Cammell Laird shipyard at ­Hebburn in Tyneside.

With six operating theatres, an ­intensive care unit, an ophthalmic unit, two CT scanners and 78 hospital beds on board, the medical teams can ­double the numbers of patients they treat.

Supplies are flown in every three weeks from warehouses in Rotterdam or Mercy Ships headquarters in ­Texas. Since February the Africa Mercy has been docked in Cotonou in Benin, West Africa, where she will stay until October before taking two months off for repairs and servicing.

All the medical staff and crew are volunteers, working anything from a few weeks to several years.

“In fact we charge them room and board so they actually have to pay to work for us. It’s quite a unique business model,” says Don.

The annals of the Mercy Ships are filled with poignant stories of lives transformed by simple surgery which takes 10 minutes in a typical Western hospital.

There is the tale of Assan and Alusan, two-year-old twin boys who were born nearly blind with congenital cataracts.

Their family had been driven from their home because of the civil war in Sierra Leone and were living in a camp for internally displaced persons when a neighbour heard that the Mercy Ship was docked in Monrovia, Liberia, last year.

Surgeon Glenn Strauss operated on the boys last April and they have fully recovered their sight. Don also remembers four blind Mexican children who regained their sight ­after cataract removal.

“They had never seen their ­mother or each other. Watching a blind ­person see for the first time is ­incredibly moving. Even the most ­experienced surgeons weep at that.” Alfred Sossou from Benin was 10 when a tumour started growing on his jaw. By the time he was 14 it weighed 5lb and had consumed his lower teeth. The boy could only eat by stuffing food down a small gap between his tongue and the ever-growing mass. Eventually it would have suffocated him. His parents had paid all they could afford to ­local witch doctors to no avail. Surgeon Gary Parker operated in 2005 and Alfred’s face has completely ­recovered and he is no longer considered to be the harbinger of evil spirits in his village.

The Mercy Ships have also pioneered surgery for women who have been damaged in childbirth. About three million are left with fistulas (tears between the bladder and vagina) after giving birth, leaving them incontinent, which in turn devalues their worth to their communities.

But what of the people the Mercy Ship medics cannot treat – those with terminal diseases? “In those cases we go to their homes and teach their relatives about hospice care; how to change dressings, give pain relief ­– how to care for the ­dying,” says Don. Mercy Ships is a Christian organisation but the ­volunteers – like the patients – can be from any faith or none.

Although he started a charity Don has ended up running the ­equivalent of a multinational. “It’s all been on‑the-job training and it wouldn’t have been possible without the ­exceptional volunteers.”