Elon Musk has announced that he will be sending engineers from both SpaceX and The Boring Company to Thailand tomorrow to try and help rescue the Wild Boar soccer team that remains trapped inside a flooded cave.
Monsoon flooding cut off their escape and prevented rescuers from finding them for nine days.
It is unclear at this point if Thai officials will accept Musk's offer for help.
Over the last couple of days, Mr Musk posited possible ways his companies could help in Thailand.
Musk says the sub would be light enough to be carried by two divers and small enough to get through narrow cave gaps.
"Primary path is basically a tiny, kid-size submarine using the liquid oxygen transfer tube of Falcon rocket as hull", Musk tweeted. The tweets show the submarine being slowly ferried underwater by a team of divers.
A spokesperson for the Boring Company told The Verge: "We are speaking with the Thai government to see how we can help, and we are sending SpaceX/Boring Company people from the U.S. to Thailand today to offer support on the ground". REUTERS/Athit Perawongmetha; SUPERIMPOSED: Elon Musk - the founder, CEO, and lead designer at SpaceX and the co-founder of Tesla - in Washington, US, July 19, 2017. But the mission has been turned into a race against time as oxygen levels fall and heavy rain is due this weekend.
And when someone asked if it had been "Confirmed to maneuver through even the most narrow passages", he answered "yes".
"Also building an inflatable tube with airlocks", he wrote.
Musk first floated plans for how he would help rescue the team on Twitter in response to a plea for help from Twitter user @MabzMagz.
The operation to rescue 12 boys and their coach from a flooded cave in Thailand kicked off early on Sunday, a couple hours after Musk had predicted his project would be complete and nearly a day earlier than he said he would be able to bring the sub to Thailand.
An air line has been installed to the cave where the group has been trapped for almost two weeks in a chamber in the Tham Luang cave complex.