Elon Musk’s “kid-size submarine” may have been too late to contribute to the rescue of 12 children and their soccer coach who were trapped in a Thai cave, but the technology could be useful in the future.

SpaceX engineers worked through the weekend to design, build and test a small submarine that could be used to bring the children out through flooded passageways.

The leak-proof aluminium rescue pod is big enough to carry one person. A nose cone helps to guard against impact, while the hull is able to withstand water pressure.

The children and their coach were all brought out of the cave yesterday – just hours ahead of the pumping equipment helping to reduce water levels broke down.

Although the small submarine was needed, Musk is sure it would have been able to do the job.

The pod has been left in Thailand to be used for other rescue missions, and the team will likely continue to develop the technology, which could be used in future rocket missions. “This could also work as an escape pod in space,” Musk tweeted.