A kitesurfer on Bracklesham Beach was airlifted to hospital on Sunday after he injured his back when he hit a groyne.
The man, in his twenties, was flown to the Royal Sussex Hospital in Brighton after the accident.
South East Ambulance spokesman Richard Airey said their crews were called to the scene at 2.30pm on Sunday.
He said: “We attended with two cars and ambulance as well as a police helicopter.
“It was a man in his twenties with suspected spinal injuries and head injuries who was taken to Royal Sussex Hospital in Brighton.”
Resident of East Bracklesham Drive, Ann MacDonald, who has been campaigning against kite surfers on Bracklesham beach for years, said: “As predicted by residents, we unfortunately had a major accident. We had several ambulances and a helicopter; I really hope the man in question is okay. He hit the groyne as he lost control of the kite.
“It is a blessing that no one else was hurt and the six children I have in our house were all at a christening with us.
“Anyone at the top of the beach could have been easily injured, as the kite fell on our fence in front.
“The man tried really hard to dig his heels in the sand, but was still dragged into the groyne. This is the third airlift in five years.”
A designated watersports zone at the beach was scrapped in June after a legal challenge by residents who feared the kitesurfers were threatening the safety of others.
James Fitch, owner of Bracklesham Boardriders, said: “It was a terrible accident and the only good thing about it is that the area was quiet so no-one else was hurt. There was a potential for it to be a lot worse.
“I do not believe the man was local but he was doing it in the right place. Kitesurfing is a sport with risk, and we all have accidents. About four years ago a guy in Witterings was in an almost identical scenario.
“Since the official designated zone was scrapped, it means there is no safe area for kite surfers, and this accident is an example of why it should be in place.”
The incident may spark further debate about kite zones in the area, and whether an area needs to be designated for the sport; residents of East Bracklesham Drive believe Medmerry, in Selsey, would be a more appropriate spot for the activity.
A Chichester District Council spokesperson says: “Our Foreshores Team was made aware of a gentleman who had hit his head and hurt his back on a groyne while kitesurfing at Bracklesham Bay on Sunday.
“They provided first aid support and helped clear the beach to allow the air ambulance to land and take the gentleman to hospital.”