A man spotted wading into the River Thames during the early hours was pulled to safety by a passer-by at Bankside, triggering an emergency launch by an RNLI lifeboat crew.
London's Tower RNLI lifeboat Hurley Burley was launched at 2.55am on Saturday 3 October to a report of a man in the water at Bankside near Tate Modern.
The RNLI lifeboat crew arrived minutes later and began a rapid search of the water and shoreline supported by police officers on the riverside.
The crew quickly spotted a man aged in his early twenties partly submerged on the water's edge with the tide rising around him.
"We put two of our lifeboat crew ashore at the same time as police officers arrived on the beach," said Keith Cima, Tower RNLI lifeboat helmsman.
"We carried out an assessment of his medical condition and put him on oxygen before placing him in the recovery position. The casualty was wet through and very cold but was responding to our voices.
"It transpired he had been spotted wading into the river by a passer-by who went into the water and pulled him out. We think it likely the casualty was under the influence of alcohol which may explain his actions.
"Our advice is never to swim in the tidal Thames in London, but doing so after drinking alcohol is particularly dangerous.
"Strong river currents flow faster than an Olympic swimmer can swim which will exhaust even the fittest of people. Cold water shock will also lead to uncontrollable gasping resulting in you gulping down river water. At this stage drowning isn't far away.'
"The man was put on an RNLI basket stretcher and taken up a set of stone steps to the embankment above where he was handed into the care of London Ambulance Service."