River Thames to the strong current of the river, but also other river users. Organised swimming events take place at various points generally upstream of Hampton Court, including Windsor, Marlow and Henley. In 2011 comedian David Walliams swam the from Lechlade to Westminster Bridge and raised over £1 million for charity. In non-tidal stretches swimming was, and still is, a leisure and fitness activity among experienced swimmers where safe, deeper outer channels are used in times of low stream. A Thames meander is a long-distance journey over all or part of the Thames by running, swimming or using any of the above
River Thames and Teddington Lock, the river forms part of the Port of London and navigation is administered by the Port of London Authority. Both the tidal river through London and the non-tidal river upstream are intensively used for leisure navigation. The non-tidal River Thames is divided into reaches by the 45 locks. The locks are staffed for the greater part of the day, but can be operated by experienced users out of hours. This part of the Thames links to existing navigations at the River Wey Navigation, the River Kennet and the Oxford Canal. All craft using it must be licensed.