A crewman was lost overboard in gale force winds off the Sussex coast this morning.
The Eastbourne lifeboat was called out at around 12.40am this morning to reports a man had fallen into the sea five miles south off Sovereign Harbour.
Police have now confirmed the man who is missing is 55 and from Kent.
The tug Endurance, with two people on board was travelling from Dover to Brighton with a 60ft motor cruiser under tow when the accident happened.
The tow was lost and the crewman was trying to re-establish it when he fell overboard.
His colleague sent out a Mayday distress call which mobilised the rescue services.
The Eastbourne lifeboat began the search close inshore off Beachy Head joined later by the Coastguard helicopter.
The Newhaven lifeboat was also asked to join the hunt for the missing person but later diverted to collect the cabin cruiser which had drifted five miles from the scene.
It was then towed to Sovereign Harbour.
The two lifeboats continued their search throughout the night and were joined at first light by mobile units from HM Coastguard.
The search was finally abandoned at 9.10am.
A Sussex Police spokeswoman said: "A 55-year-old man has been reported missing at sea in the early hours of this morning.
"Sussex Police received a report at 1.55am that a man had gone overboard from a Tugboat that was five miles off Beachy Head and en route to Brighton.
Emergency services including the Coastguard helicopter and Eastbourne Lifeboat are continuing with their search this morning.
"The other crew member, a 37-year-old man from Kent, arrived on dry land at 3.20am and is uninjured."