I have just added this to the map of places to fly your drone at Drone Scene:
Land owner permission requirements unknown.
From A35 follow signs to Mudeford and then Mudeford Quay.
Christchurch Harbour is midway between the Solent and Poole Harbour, providing access to one of the most popular areas for boating on the south coast.
It was formed about 7,000 years ago. Christchurch Quay and Quomps lie in the upper reaches of the harbour. The entrance to the harbour, known as ‘The Run’, is flanked by Mudeford Quay to the north and Mudeford Sandbank to the south.
The harbour SSSI (Site of Special Scientific Interest) is very popular with birdwatchers and includes the estuary of the rivers Stour and Avon as well as Hengistbury Head - a total of 870 acres.