A medic and three Thai Navy Seals who have stayed with the boys on a small, dry shelf deep in the flooded cave will also come out, he said. He said experience gained during the successful extractions in the preceding two days would allow them to work faster and more efficiently.
Local governor Narongsak Osatanakorn said Tuesday's rescue operation began just after 10am local time and involves 19 divers.
Officials lavished praise on the Thai and global divers who, in pairs of two, executed the risky rescue mission, guiding the boys, who could barely swim and had no diving experience, through a treacherous 4-kilometer-long (2 1/2-mile) escape route that twisted and turned through the cavern.
Torrential rain fell overnight and through the morning in the area of the Tham Luang cave complex, where the Wild Boars youth soccer team had been stranded on June 23.
The eight boys rescued on Monday are in good health overall and some have asked for chocolate bread for breakfast, officials said on Tuesday.
They are still being quarantined from their parents because of the risk of infection and will probably be kept in hospital for a week to undergo tests, officials said.
It is believed that the second lot of boys are in better health than the first four who were brought out first because they were deemed the "weakest".
It hasn't even been 24 hours since rescuers pulled the last boy of the trapped Wild Boars junior soccer team from Thailand's Tham Luang Cave - but there's already talk of immortalizing their incredible survival and rescue story on the silver screen.More news: Wimbledon: Serena Williams advances as top ten fall
"All eight are in good health, no fever. everyone is in a good mental state", Jedsada Chokdamrongsuk, permanent secretary of the public health ministry, told reporters Tuesday at Chiang Rai hospital where the boys were recuperating.
Writing in elegant Thai script, the boys urged their parents not to worry, adding that they hoped they wouldn't get too much homework after being rescued and couldn't wait to eat their favorite foods again.
Two of the first group had a lung infection as well, and Thongchai said they would need medicine for seven days.
Narongsak said he was grateful for Musk's support but the equipment was impractical for the rescue mission.
"The kids are footballers so they have high immune systems", he added.
The cave evacuation wasn't the first time some of the boys had faced and escaped a great peril.
Musk said on Twitter after the rescue: "Great news that they made it out safely". "Mini-sub is ready if needed".
Prime Minister Prayuth Chan-ocha visited the cave to inspect the operation, with navy rescuers giving him a rousing cheer.