Vets looking after Terri the turtle say there is a 50% chance it will survive but they are "doing all they can".
It was found yesterday on the stretch of beach between the Dicq shack and Rice bowl and was taken to the nearby New Era Veterinary Hospital.
The young loggerhead turtle weighs about 25 kilograms and should be sunning himself in the Canary Islands, but strong storms had blown him off course.
It is still fighting hypothermia and needs to be warmed up very slowly.
However, one vet told our reporter Katie Robinson that Terri's condition is critical.
Loggerhead turtles are named for their large heads that support powerful jaw muscles.
They are the most common turtle in the Mediterranean, nesting on beaches from Greece and Turkey to Israel and Libya.
It is very rare to see them in the Channel because the temperatures here are usually too cold for them to live.