A French inventor and adventurer who in 2019 crossed the English Channel on board a jet-powered hoverboard has said he is feeling well after a dramatic plunge into a lake from mid-air in southwest France.

Franky Zapata had fulfilled a lifelong dream by zooming across the Channel on a "flyboard" he developed himself and in 2019 also stunned onlookers including President Emmanuel Macron by soaring into the Paris skies during the annual Bastille Day parade.

But during a demonstration event yesterday in Biscarosse in southwest France, Mr Zapata had dramatically plunged some 15 metres into a lake after initially soaring into the air without any problem.

Regional press reports said he had been hospitalised after being taken away on a stretcher. But there was no detail on what injuries he may have sustained.

The former jet-ski champion lost control of his contraption (file pic)

It was also not immediately clear what had caused Mr Zapata, 43, and a former jet-ski champion, to lose control of his contraption.

"I am doing fine," Mr Zapata wrote on his social media accounts, thanking the public for their support and emergency services for their assistance.

"This reminds us that we are not birds and that if we are not excellent then gravity wins.

"We learn something from our mistakes and we should not think we can change mobility without making some," he added.