The rescue of the Thai football team from a flooded cave was a mini-saga that had the world holding its breath. Everyone wondered not only could they be saved, but how, and Elon Musk thought he had the answer in a submersible he built on-the-spot. As fate would have it, by the time Musk arrived with his sub, the rescue was basically over. There was nothing for his submarine to do but sit on dry land and become an eventual gift to the Thai SEAL Teams. Not everyone was impressed with his effort, however.
The early buzz on the ground was that it didn't seem like Musk's sub would work if it had been tried out in the cave. This was a concern that some experienced divers had expressed before the submersible was even built. There was never any talk of the actual logistics of it operating in the cavernous environment, just that it was on the way with Musk.
Diver Vern Unsworth, who was instrumental in the rescue of the team and their coach, has echoed those early concerns and went a little farther than just saying that the submersible wouldn't work. He wasn't the only one on the scene that was critical of Musk's sub. Mediaite reported that Unsworth had some choice words for Musk.