Meanwhile FIFA has sent a letter to the president of the Football Association of Thailand offering its "deepest sympathies and support" to the families of young soccer players and their coach trapped in cave in the country's north.
The boys were trapped in the cave for 10 days before a group of cave divers discovered them alive last week.
He wrote that engineers from two of his companies, the aerospace manufacturer SpaceX and the tunnel-construction company Boring Company, were leaving for Thailand on Saturday to offer assistance to the Thai government.
Notably, the serial entrepreneur is actively engaged in below-surface tunneling in the United States, via his Boring Company, which is developing a series of underground tunnels in some major cities to make room for Loop, Musk's idea for a next-generation high-speed transit system.
It is not clear whether the Thai government is willing to use Musk's solution as opposed to the expertise of its divers.
Earlier, Thai authorities had planned to have all the 13 dive out of the cave, but the death of a former Thai Navy SEAL member early yesterday appears to have made planners reconsider their options. The billionaire engineer is now in talks with Thai authorities to establish how the resources at his disposal - including those associated with TBC and SpaceX - could help with the cave rescue.
He then considered that it was "maybe worth trying" inserting a nylon tube into the cave network to create an air tunnel underwater.
In later tweets, Musk said that the submarine he is working on has four handles in the front and four in the rear, along with four air tank connections.
There are two or three engineers on the ground in Thailand, with more on the way, the spokesman said.
The boys, ages 11-16, and their 25-year-old became stranded when they went exploring in the cave after a practice game.