The rescue person is now recovering in Altnagelvin hospital.
Foyle Search and Rescue say on its Facebook page: “At 5.38 am on Tuesday 19/5/2020 Foyle Search & Rescues Pager system was activated by the Police Service of Northern Ireland to reports a person had entered the water.
“Our Emergency Response Teams responded via Rapid Response Vehicle, two boats a Jetski and base support crew.
“On arrival at scene the PSNI had deployed a lifebuoy which was keeping the person secured and afloat with units of the Northern Ireland Fire & Rescue Service in situ.
“FSR boat crew and Jetski in Personal Protective Equipment commenced a rescue transferring the person back to Prehen where Emergency First Responders administered treatment. T
“The person was then transferred to the Northern Ireland Ambulance Service and onward to Hospital.
“Our Emergency Response Teams conducted a debrief with all equipment sanitised and re located to base being returned to operational readiness with FSR personnel stood down at 07:20hrs.
“This was a multi agency response resulting in a successful rescue, appreciation to CCTV and all relevant agencies involved.
“If you need support and help please don’t do it alone reach out:
“Lifeline 0808 808 8000
“Samaritans 116 123
“CCIS 02871 262 300.”