The man has been taken to hospital after being pulled from the sea by a coastguard rescue swimmer.
The UK coastguard received a call at 7.05am from a friend of the man saying he had lost sight of the 21-year-old man.
Coastguard Rescue Teams from Newhaven and Shoreham were tasked to search for the man, along with RNLI lifeboats from Brighton and Newhaven, and the Coastguard Rescue helicopter from Solent.
Police officers completing a shoreline search spotted the man close to shore and a crew member went into the water to rescue the man within 45 minutes of the start of the search.
A crewman managed to locate the casualty and, with the help of Newhaven Coastguard, got the casualty ashore and passed him over to South East Coast Ambulance Service. Brighton Lifeboat were stood down at 7.56am.
Daniel Gurr, volunteer helmsman at Brighton RNLI, said: “Given conditions on scene the search was very challenging with a large a shore dump and the lifeboat needing to go close into shore. All teams involved with the search worked well together and our thoughts are now with the gentleman and his family.”
The man’s condition is not known at this time.
Steven Mann, Senior Maritime Operations Officer from the National Maritime Operation Centre in Fareham which co-ordinated the search, said: “We have specialist software which helps construct a search area where someone might be in the water and is very accurate.
“On this occasion it helped us to work out very quickly where this man should be and task the units to the area with the highest probability of detection.”
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