They would take an inflatable boat every morning to get to Ambrym, where they would set up a clinic, he said.
"People were coming from all the little villages from all over the island.
"It was pretty remote, there was no plumbing or anything on the island. People are still living in grass huts.
"Apart for guys in little canoes, nobody except our big boat has probably ever been out there."
Mr Duthie estimated 4000 people lived in the region, although population numbers had never been recorded properly.
There were plenty of small villages with 100-200 people, but then also villages with only one or two people, he said.
"Politically it is really interesting, you can become your own chief and start your own village."
If there were more than 100 people in a village, they would have a basic concrete building and maybe a solar panel mount, so people could have basic cellphones, he said.
Mr Duthie said they came across patients with tuberculosis, yaws - a bacterial infection - elephantiasis and some unexpected conditions like people with high-blood pressure, dementia and Parkinson's disease.
"They started getting Western canned corned beef, which is really poor-quality meat, high fat, high salt, so they have started getting startling high-blood pressure ... and getting the strokes that the people are getting in the West."
Mr Duthie said one woman had dementia, which was rare in the area.
"People don't live long enough to get it there and one of the saddest things was a lady who had early Parkinson's disease.
"There is just no way she is going to get the medication she is going to need for it.
"One of the nurses, who was taking photos, came over to us and when she heard the diagnosis she had to wander off in a hurry. She just got choked up, knowing what it would mean for this woman.
"We had a good translator and we were able to tell this woman her thoughts would be fine and she would still be herself mentally, but her body was starting to fail."
Mr Duthie said the experiences he had with his family were amazing, too.
One day they trekked 18km up a volcano to look into lava lake, he said.
Each evening they were also able to go snorkelling around the Pacific Hope, after swinging off a 20-metre high crane on the ship.
They were also able to organise house visits to see people who were too disabled to come and see them.
That provided great walks through the jungle and the villages, he said.
"They are a very caring community and would go out of their way to take care of sick people."
"We're starting to off-load all these Western diseases to these people, so it's good to be there now when it's just starting to creep in, so they know that this stuff is really bad for them - to give them that education."
