CBBC presenter Holly Walsh has broken her arm after leaping into the sea in a homemade helicopter.
The stunt was part of the Worthing Birdman festival where competitors try to build and fly their own aircraft.
Around 10,000 people watched on as Holly and her co-pilot crashed into the water.
A lifeboat arrived at the scene and Holly was taken to hospital in an ambulance. She is being treated for her injured arm and shoulder.
Holly presented with Dunceton the Brain
Shoreham lifeboat spokesman Dave Cassan said: "It appears she entered the water wrongly."
Holly took part in the festival to raise money for charity.
Afterwards Holly thanked everyone who took care of her saying: "I couldn't have been looked after better by medics and the organisers."