Sam Teller, the spokesperson for the Boring Company, said four company engineers were "offering support in any way the government deems useful".
Authorities temporarily stopped rescue efforts on Monday to replenish air tanks along the cave's perilous exit course. Of the 12 young prisoners at the moment, managed to free four.
The area outside the Chiang Rai hospital was cordoned off by police.
The rescue operation commenced on Sunday afternoon, as monsoonal rain threatened to further flood the cave, making a rescue impossible, and possibly depriving the boys of oxygen.
The dramatic and unsafe rescue at the Tham Luang cave in the northern province of Chiang Rai was launched on Sunday and four boys were brought out that day.
Musk then started brainstorming ideas to help via tweet. The tweets show the submarine being slowly ferried underwater by a team of divers.
"Will continue testing in LA in case needed later or somewhere else in the future", he wrote.
Narongsak said each boy was outfitted in a full scuba face mask and was escorted by two seasoned divers.
SBS News understands that the boys are in a sterile, isolated section of Chiang Rai's provincial hospital.
The four boys emerged by 8 p.m., quite a bit ahead of schedule -and all the more remarkable because the boys are novice swimmers, with no diving experience.
Narongsak said the healthiest have been taken out first, and the next phase of the operation would start in 10-20 hours.
The first members of a youth soccer team trapped with their coach in a flooded cave in northern Thailand have been rescued and are on their way to the hospital, local officials said on Sunday.
During a brief break in the weather, rescuers were able to pump some of the excess water out of the Tham Luang cave in the Chiang Rai province and rescue at least four boys, who had been trapped in there for over two weeks.
The operation began at 10 a.m.
The first four boys who were trapped in the cave in Thailand have been rescued and are in "perfect" health. The boys were transferred by helicopter and ambulance to a hospital where they were being treated, but officials did not disclose details of their condition.
Eight boys are still inside the cave and along with the team coach. They had been missing for 10 days before they were discovered. The interior minister Anupong Paojinda was noted saying that officials are meeting on Monday morning to plan the next stage of the operation in order to rescue the remaining 9 students from the cave.
"They can not decide how many of them will be able to come out for the first operation".
Authorities have said it takes roughly 11 hours to do a round-trip from the cave entrance to where the boys are huddled on a muddy bank.
Boring Company CEO Elon Musk is now part of an global team of engineers, divers, and other experts working to rescue a group of boys from a Tham Luang Nang Non cave in Thailand.
"From the situation assessment, we need to use the area to help victims".
He said all the boys were in good condition. The governor recently said that water levels were at their lowest. Gen. Chalongchai Chaiyakam said.
Narongsak said rescuers had to tighten a guide rope as part of their preparations for Monday's operation. "The war ends when we win all three battles - the battles to search, rescue and send them home".
Two ambulances left the cave and drove to a nearby helipad, and a helicopter was seen taking off.
A frantic rescue mission was hatched in the week since they were found.
"I mean, we're a big country and Thailand is a small country". On 23rd June, 12 members of a junior soccer team and their coach visited Tham Luang Cave which is a popular tourist destination in Thailand.
The daring rescue mission began early Sunday morning more than 2 weeks after the team became trapped in the cave. So far, two boys have confirmed lung infections.
Experienced cave rescue experts consider an underwater escape a last resort, especially with people untrained in diving, as the boys are.
The path out is considered especially complicated because of twists and turns in narrow, flooded passageways. The attempts were not successful early on but there has been a break from the rain.