Although there are several small sandy beaches, swimming is not recommended within the Harbour. There can be considerable boat traffic and much of the water's edge consists of mud flats, which makes swimming difficult and sometimes unpleasant. Swimming is much safer and more enjoyable on the excellent sandy beaches just outside the Harbour at Sandbanks, Flaghead, Shell Bay and Studland.
Recreational diving in Poole Harbour has its own problems - there is hardly any deep water other than the navigation channels! Some recreational diving and training does occur in safer areas of the Harbour, but this is usually less than interesting due to the poor visibility underwater. If you wish to dive in Poole Harbour, remember, some areas can become very congested, so for your own safety: