RNLI rescue crews pulled a man from the River Thames on Wednesday evening after he was spotted clinging to a rubbish barge.
The misty image was retweeted as far afield as Lapland, Barbados and Korea.
Three hundred at seventy people were rescued by the RNLI in London last year - yet only 16% of us know they patrol the capital.
A stunning image of London's red morning sky has been captured by London's lifeboat service.
A lifeboat helmsman took the image at the end of his night shift, Tower RNLI said.
A misty image of Tower Bridge taken last week by the lifeboat service has been retweeted over 29,000 times.
– Toni Scarr, volunteer lifeboat crew member for Tower RNLI
"This incident has been recorded as a life saved as there were no other boats in the area at the time and I don’t think anyone was actually aware he was in the water.
He was incredibly fortunate in that respect.
We still don’t know how he came to be in the water but due to an unusual twist of fate we managed to avoid one more fatality on the River Thames last night.
That first person who was threatening to jump from London Bridge probably has no idea that, all things considered, he saved another man’s life."
A man threatening to throw himself into the Thames inadvertently saved the life of a stranger who was drowning in the river below.
Tower RNLI crew say they would never have spotted a person in the water if it wasn't for the callout to reports of someone on a ledge and ready to jump at London Bridge late on Wednesday evening.
By the time they arrived police had managed to talk the man down, but the crew spotted someone else on the bridge pointing towards the water.
It was then that they spotted the person in the river, desperately struggling to keep his head above the water as he was dragged down by a large duffel coat.
When they pulled him out, the crew found he was suffering from hypothermia and he was taken to hospital.
The RNLI say they don't know how the person ended up in the water, but he was said to have been alert and apologetic when he was attended to by crews.
London lifeboat crews saved 372 people last year, 25 of whom would almost certainly have died without the intervention of a lifeboat.
Annual statistics on the deployment of lifeboat crews reveal that Tower station near Waterloo Bridge was the busiest in the whole of the UK and Ireland last year, with crews called out almost 500 times.
A man has been saved from the icy cold waters of the Thames by lifeboat after being spotted at Battersea. A team from the Chiswick and Tower RNLI was sent to pull him to safety last night. He needed mouth-to-mouth recusitation.
Nine teams of people are competing against each other to pull a 14-tonne, 11-and-a-half metre lifeboat, a quarter-of-a-mile, in the quickest time possible.
It is all to raise as much money as possible for the RNLI.
The lifeboat will sit on a low loader during the event, creating a massive 37 tonnes for the teams to pull through the London park.