A British diver involved in the rescue of a Thai soccer team from the flooded Tham Luang cave system has dismissed Tesla CEO Elon Musk’s proposed mini-submarine as a PR stunt.

Vern Unsworth, 63, who played a key role in helping the young footballers safely out of the cave, rejected Musk’s idea to use the mini-submarine for the rescue mission.

 “He can stick his submarine where it hurts,” Mr Unsworth told CNN when asked what he thought of the invention.

“It had absolutely no chance of working,” he said.

Mr Unsworth said Musk had no idea of what the cave passage was like.  “The submarine, I believe, was about five foot six long, rigid, so it wouldn’t have gone round corners or round any obstacles,” he explained.

“It wouldn’t have made the first 50 metres into the cave from the dive start point. Just a PR stunt.”

Mr Musk had tweeted about the rescue and the device his team had built for days last week as Thai authorities and an international team were working against the clock to extract the boys and their coach from the caverns.

When asked about the mini-sub, rescue command chief Governor Narongsak Osotthanakorn said it was not suitable for the mission.  His comments apparently irked Musk.