The boys, some of whom don't know how to swim, have also been taught diving techniques to prepare them for their hard journey home.
Thirteen foreign divers and five members of Thailand's elite navy SEAL unit make up the main team guiding the boys to safety.
"After 16 days of waiting ... today, we saw the boys' faces", Narongsak said.
The operation paused Sunday evening so that rescue teams could refresh the supply of air tanks that have been placed along the escape route inside the cave, Narongsak said.
Karadzic was hopeful that Monday's operation would go as smoothly.
The first boy of the day, and fifth overall, was removed from the cave at 5 p.m., a source close to the operation told ABC News.
It had been assumed that the four extracted yesterday were boys, but it emerged that the fourth person taken out was the coach, Mr Ekapol. "I've been involved in cave rescue for 30 years and I can not even think of one that was more complicated". A total of 90 divers, including 50 foreigners, have been involved in the entire operation, Narongsak said.
The extraction of the four on Monday followed a similar pattern to the previous day, with the youngsters emerging in quick succession just before nightfall after navigating a treacherous escape route of more than four kilometres (2.5 miles) that included extremely narrow and flooded tunnels.
An ambulance carrying one of the boys rescued from the Tham Luang cave network on Sunday. Two of them possibly have a lung infection but all eight are generally "healthy and smiling", he said. Monday's operation began at 11 a.m. and took nine hours, two fewer than Sunday, with rescuers helped by the experience they've accumulated, Narongsak told a news conference punctuated with rounds of applause. The rescued children were taken to the hospital, and officials said early Monday that they are strong and safe but need to undergo detailed medical checks.More news: 5 things to know about Amazon Prime day
Former Thai navy SEAL Saman Kunan passed out making the dive on Friday and died.
The rescued kids are now in the hospital, where they should receive the proper care before being released to their families.
After reaching the area where the boys were trapped, the divers used a rope, which was connected to the outside of the cave, to guide them through the exit way. An international-level rescue mission began soon after, with hundreds of experts and military personnel from various countries arriving at the spot.
Thai officials are not only racing against worsening weather, but also lowered oxygen levels in the underground complex.
The SEALs, which have stationed divers and medics with the boys for the last week, posted a message on their Facebook page on Sunday promising to bring the group back safely.
There are now five members of the Wild Boar football team now left in the cave.
The boys are wearing special diving masks that cover their whole face as this helps them breathe more easily from their oxygen tanks. Heavy rain flooded the cave entrance after they entered it, trapping them inside.
"They may show extremes in behaviors. they (may) sleep too much or have difficulty sleeping", says Aten, who is not involved in the boys' treatment.