As an international coalition of divers continued to rescue a Thai soccer team and their coach from a cave Monday, Tesla CEO Elon Musk was trying to help in his own inimitable way.
Musk on Sunday tweeted that he was sending a "kid-size submarine" to the rescuers in the hopes that it would be "useful." As of this midday Monday, eight of the 12 boys had been rescued, and operations were ongoing.
Last week, Musk tweeted that he was sending a team of SpaceX and Boring Company engineers to Chiang Rai in northern Thailand on Saturday to help rescue efforts, supplying technology such as Tesla Powerwall batteries and pumps for removing water.
"Mini sub arriving in about 17 hours," Musk tweeted Sunday. "Hopefully useful. If not, perhaps it will be in a future situation."
The reason a submarine of any size would be helpful to the rescuers is because exiting the cave requires negotiating long stretches under water, and some of the young Thai players do not know how to swim.
To date, each rescued boy has been escorted through the labyrinthine cave by two divers, each of them holding an oxygen tank that feeds to the survivor's mask.
In a series of tweets in the past few days, Musk chronicled the development of his custom-built mini-sub.
Using a tube from a SpaceX Falcon rocket, Musk and a team of his SpaceX engineers created an aluminum pod light enough to be carried by two divers and small enough to squeeze through all of the cave's often exceedingly narrow passageways.
Musk posted videos and photos of divers testing out the submarine in a Los Angeles pool. In the videos, the divers move the mini-sub through a narrow passageway, simulating its use for the narrow caves.
The submarine weighs about 90 pounds dry and holds four oxygen tanks. It is outfitted with grips along the hull for divers to hold on to, according to his tweets.
Musk tweeted that the pod's design was based on feedback from some of the cave divers in Thailand. He also said that a shorter version of the pod was almost complete.
The submarine has been dubbed 'Wild Boar,' named after the young boys' soccer team.
Even if Musk's mini-sub is never used in the Thai rescue, the entrepreneur suggested its development has not been in vain. Musk's SpaceX company is winning government contracts to send payloads into orbit, but his real mission is to colonize Mars.
"With some mods, this (mini-sub) could even work as an escape pod in space," Musk tweeted.