A 19-year-old woman has been taken to St Richards Hospital after being pulled from the water at West Wittering beach this afternoon.
Emergency services including a coastguard helicopter rushed to the scene near Beach Pound Road at about 2.45pm.
Sussex Police has confirmed the casualty was a 19-year-old woman.
Selsey Coastguard, which initially reported the individual was a child, has published an updated statement on its Facebook page: “Team paged to an unconscious person who had been pulled from the water at West Wittering Beach.
“Lifeguards, Ambulance Service, Coastguard Helicopter Rescue 175, Police and Hayling Lifeboat were also on scene.
“The casualty regained consciousness and was breathing and taken to hospital by ambulance.”
Onlooker Victoria Bastable, 26, described the scene.
She said: “The lifeguards were amazing. The lifeguard came up on his buggy and that was right in front of me. He looked through his binoculars and signalled to the other lifeguards.
“Within seconds he was running towards the sea. I have never seen anybody move so quickly.
“You could see a head bobbing, I just thought it was someone swimming. It was a young woman.
“He had a lifeguard float and pulled her out of the sea. There was at least ten lifeguards there within a minute, and a woman ran over with a defibrillator.
“Within ten minutes the helicopter was there and they took her off.”
While another witness, Victoria Whitfield, 28, of West Wittering, said: “I’ve lived here all my life and I’ve never seen anything like that. The current was particularly strong today, and that young lad did so well to get to her so quickly and pull her out.
“We’re so lucky to have such a brilliant lifeguard team.”
A spokesperson for South East Coast Ambulance Service confirmed paramedics were called to the beach to reports a person had been pulled from the water.
An ambulance and three cars were sent to the scene, where a community first responder and other emergency services were also in attendance, the spokesman said.
He said the person was treated at the scene had been taken to hospital in a 'potentially serious' condition.
Witnesses at the scene have said a woman was pulled from the water by lifeguards, who administered first aid.
A spokesperson for HM Coastguard said it was informed of an incident at around 2.45pm today involving a person in the water at West Wittering.
They said, “Hayling Island Coastguard Rescue Team and RNLI lifeboat were sent to assist lifeguards on the scene. HM Coastguard’s search and rescue helicopter from Lydd was also sent.
“The casualty was put into the care of South East Coast Ambulance service and taken to hospital. We have no more information at this time.”
In an emergency out at sea, on the beach, or along the coast dial 999 and ask for the Coastguard.