Police, Paramedics, 2 Coastguard Rescue Teams and Sandown & Shanklin Independent Lifeboat (SSILB) are all on scene at the Esplanade in Sandown.
5 Coastguard Officers from Bembridge and Ventnor have donned water rescue equipment and have entered the water, supported by Police on the shore.
The alarm was raised sometime before 02:30.
The incident is unfolding less than 50m off the shoreline.
UPDATE @ 03:40 – 1 male has been successfully rescued thanks to the efforts of Coastguard officers and volunteer lifeboat crewman from SSILB.
He has been handed over to the Police and in turn passed into the care of the Isle of Wight Ambulance Service.
The individual is thought to be cold but otherwise uninjured.
Rescue teams are now standing down from the incident.
UPDATE @ 09:53 – Hampshire Constabulary have confirmed that they were called at 02:16 following a concern for welfare call for a man in his 20s.