Musk proposes mini-submarine to save Thai cave boys

American tech entrepreneur Elon Musk has proposed a mini-submarine to save the boys trapped inside a flooded Thai cave, floating the idea on social media while linking it to his space exploration business.

After garnering headlines with initial ideas of installing a giant air tube inside the cave complex and using his firm's penetrating radar to dig holes to reach the boys, Musk's latest concept is the pod.

"Primary path is basically a tiny, kid-size submarine using the liquid oxygen transfer tube of Falcon rocket as hull," Musk said in a tweet to his 22 million followers. "Light enough to be carried by 2 divers, small enough to get through narrow gaps. Extremely robust."