They have been on mission trips before but this one was different.
There was no bringing supplies to villages or doing construction.
Matthew and Sarah Robertson spent most of their time from June 10 to July 24 in a ship's kitchen preparing meals for more than 400 people from 45 nations.
The ship was the 16,572-ton Africa Mercy, the world's largest non-governmental hospital ship.
At the time, it was docked at Las Palmas in the Canary Islands off the coast of Morocco. There, it was being prepared for a trip to the Congo where it will be docked for 10 months.
Surgeries and dental procedures are done for the needy aboard the vessel. There is a ward with 84 beds for patients. Workers also go ashore into villages and conduct clinics. Local medical personnel receive training.
Matthew said some Africans walk hundreds of miles for a surgery.
The Mercy Ships charity was begun in 1978 and since that time more than 2.4 million people have been medical beneficiaries.
The Robertsons, who live in Cataula, Ga., cooked for the doctors, nurses and other crew members, who receive no monetary benefit and must pay for their own needs, as did the couple. Some volunteer for years on the ship.
"We cooked lunch and dinner," Sarah said. "The work day was about 12 hours."
The Robertsons, who will celebrate their third wedding anniversary in December, own the Marco's Pizza restaurant on Double Churches Road in Columbus.
They are both natives of the area. Sarah, 24, was raised in Harris County and Matthew, 29, in Columbus.
They met at Wynnbrook Baptist Church where both led worship for youth. They currently attend My Church of Columbus.
Both have been on missions to places such as Costa Rica. As a teen, Matthew visited Africa. He said the trip left a big impression on him.
"It was then I decided I wanted to help others," he said.
He wishes more people could see the great poverty he has seen in other countries.
"It really grounds you," he said. "We are blessed as a nation. In this country, we take so much for granted. But it is not all about us."
His wife agreed.
"You see these people who have very little and yet there is a lot of joy. That is because their joy does not come from material things. It is a special mindset."
The Robertsons were inspired to go on the Africa Mercy by the story of Nick and Dianna Cash of Columbus, who sold their belongings and took their children to work in the program. The Robertsons know the Cash family through Teen Advisors, which employed both Nick and Dianna.
During their time on the ship, the Robertsons lived in a 10 x 10 cabin.
"There were no windows," Sarah said.
She said cooks had to be creative.
"We did not waste anything. If we had some chicken left over, we used it for chicken soup. We used everything we had."
Crews were doing maintenance on the ship so power was often lost as well as water.
"Losing power or water is not good when you are cooking for 400 people," Matthew said, laughing.
Using a laptop, Matthew was still able to run his restaurant from the ship and had great confidence in his employees back home.
Sarah said it was an "incredible experience" meeting people from all over the world.
While they were serving the crew, Matthew and Sarah were also serving God, the same as on other missions in which they have participated. They feel strongly that helping others is what they have been called to do.
"We love because He first loved us," Sarah said. "We are serving the body of Christ and feel fortunate that we are in the position to do so."