People strolling along the Thames Path on Saturday afternoon got a surprise when Tower Bridge was raised to allow one of the three Woolwich Ferry vessels to moor at Tower Pier opposite City Hall.
The John Burns stayed in the Upper Pool of London all night before returning to its Woolwich berth at 5.30am on Sunday.
One message on Twitter describes an all-night event involving "180 dancers on deck".
There was no service on the Woolwich Ferry this weekend due to maintenance work on the north and south ferry terminals.
One of the Woolwich Ferry vessels often passes through Tower Bridge in the summer months as part of an annual charity event organised by the ferry crews, but this overnight charter is more unusual.