A yachtsman was flown to Auckland City Hospital yesterday after becoming ill about 4km north of Waiheke Island.

The Auckland Coastguard Lion Foundation Rescue vessel found the yacht in rough seas about 2pm and the police launch Deodar III brought out a paramedic from the Westpac Rescue Helicopter.

The man, aged 71, was then flown by helicopter to the hospital where his condition was described as moderate.