A diver airlifted to Chichester after suffering suspected bends on returning to Sovereign Harbour on Saturday afternoon.
Dover Coastguard received the emergency call just before 4pm and immediately tasked the Eastbourne Rescue Team.
The ambulance service was also tasked and the diver was put on oxygen.
Eastbourne coastguard escorted the ambulance under emergency conditions to Eastbourne DGH where the casualty was transferred to the coastguard helicopter that had been tasked from its base at Lee on Solent and was flown to the decompression chamber at Chichester.
Eastbourne Coastguard said, “This is not a particularly uncommon occurrence and we do deal with several such incidents throughout the season especially when the weather is warm and a lot of deep diving takes place in the channel.”
The condition of the casualty is improving.