MAE SAI, Thailand — The slender boys in soccer uniforms were huddled on the floor of the cave when British divers emerged from the murky water.
As his bright light flickered from one boy to another, one of the divers called out, “How many of you?”
“Thirteen,” one of them answered.
“Brilliant,” the diver said.
After being trapped for 10 days in a flooded cave complex in northern Thailand, and after an enormous search effort that had transfixed Thailand and the world, the missing 12 boys and their soccer coach had finally been found.
In a brief video that was posted on the Facebook page of Thailand Navy SEALs, the boys and their coach seemed in surprisingly good condition. Some of them sat and some stood as they spoke with the diver.
The group had been the focus of a search-and-rescue operation ever since they disappeared missing in the Tham Luang Nang Non cave complex on June 23 and were trapped inside by rising floodwaters.
Officials said the next challenge will be getting the group out of the flooded cave in their weakened condition and without training as scuba divers. The boys range in age from 11 to 16, and their coach is 25.
The governor of Chiang Rai province, Narongsak Osottanakorn, who is overseeing the search-and-rescue operation, said Tuesday morning that the 13 people who had been missing have all had an ‘‘informal’’ medical evaluation inside the cave and most are in stable condition and none are in critical condition.
Narongsak said that a SEAL team will make the final call on an evacuation method. He said one being considered is for the group to be coached to swim using special breathing masks.
He said other efforts will continue, such as draining water from the cave and exploring the mountainside for shafts and other entrances to the caverns below.
“I assure you we found them,” Narongsak told reporters. “After we have the doctor assess their condition, they are going to give them treatment for them to able to move. Then we are going to decide next how to move them.”
The two British divers who were first to reach the boys, both experts in cave rescues, were John Volanthen and Rick Stanton, according to Bill Whitehouse, vice chairman of the British Cave Rescue Council.
Divers were finally able to reach the group after enlarging a narrow, submerged passageway that had been too small for them to get through while wearing their air tanks.
Earlier, crews had used huge pumps to reduce the water level, and divers had placed guide ropes and air tanks along the route to reach the site of the trapped boys.
The rescue team was international, including 30 members of the US military.
King Maha Vajiralongkorn Bodindradebayavarangkun has been following events closely, helping to focus the attention of government officials.
The boys’ first question when the diver arrived was whether they could leave right away. They also wanted to know how long they had been in the cave.
The diver explained the cave was flooded, and it would take some to get them out. But he assured them that other divers would soon be bringing food and supplies.
“Many people are coming,” he said. “We are the first.”
Kham Phromthep, whose son was among the boys trapped in the cave, said he was ecstatic when he saw his son in the video. “I am very happy to see his face among the other faces,” he said.
Aisha Wiboonrungrueng, the mother of 11-year-old Chanin Wiboonrungrueng, smiled and hugged her family as word of their discovery spread.
Experts in cave rescues from around the world had gathered at the site. An official Australian group has followed the US military team, British cave experts, Chinese rescuers, and groups from several other countries.
Rescue officials had spent much of Monday making preparations for a final push to locate the lost boys and the coach. They found them about 300 to 400 yards past a section of the cave that was on higher ground.
Divers had been stymied repeatedly by rising water that forced them to withdraw for safety reasons. When water levels fell Sunday, the divers went forward with a more methodical approach, deploying a rope line and extra oxygen supplies along the route to allow the divers to operate.
Teams worked to pump water out of the cave as well as divert groundwater. Other efforts have focused on finding shafts on the mountainside that might serve as a back door to the blocked-off areas.
Teams have been combing the mountainside looking for fissure that might lead to such shafts. Several have been found and explorers have been able to descend into some.
In the 5-minute video, the boys, clad in the soccer uniforms they entered the cave in, responded well to questions from one of the rescuers. They also asked questions of their own.
‘‘You are very strong,’’ the British rescuer says to them in English. One of the boys asks what day it is, and the rescuer responds, ‘‘Monday. Monday. You have been here — 10 days.
One of the boys says in Thai: ‘‘Oh, they want to take a picture; tell him that we’re hungry. I haven’t had anything to eat.’’
Then the boy breaks into simple English, saying, ‘‘Eat, eat, eat,’’ to which another voice responds in Thai that he already told that to the rescuer.
Anmar Mirza, coordinator of the US National Cave Rescue Commission, told the Associated Press that many challenges remain for the rescuers. He said that supplying the boys and their coach in place for a while might be the safest course, although supply runs also pose risks.
‘‘Trying to take nondivers through a cave is one of the most dangerous situations possible, even if the dives are relatively easy,’’ Mirza said.
Prime Minister Prayuth Chan-ocha thanked the international experts and rescuers who helped locate the missing for their ‘‘tremendous efforts.’’
‘‘The Royal Thai Government and the Thai people are grateful for this support and cooperation, and we all wish the team a safe and speedy recovery,’’ Prayuth said.