https://www.cnet.com/news/watch-elon-musks-thai-cave-rescue-submarine-in-action/

The rescue operation to save a Thai soccer team from the flooded Tham Luang Nang Non caves in northern Thailand began in earnest on Sunday, with an experienced team of divers rescuing four of the 13 members.

Before the current rescue mission began, Elon Musk tweeted that he was designing an "escape pod" built from "the liquid oxygen transfer tube" of a SpaceX Falcon rocket that could be used as a submarine. Musk, head of Tesla and the Boring Company, tweeted that the tube would be "light enough to be carried by 2 divers, small enough to get through narrow gaps" and "extremely robust."