Around 60 spectators were rescued by the RNLI while watching the university Boat Race beside the River Thames on Saturday.
Dozens became stranded as they stood on the foreshore of the Thames and were trapped by the rising tide along Hammersmith, Chiswick and Barnes.
According to the BBC, an eight-year-old boy was rescued when he was separated from his parents.
Following the women's race, seven people were evacuated from Chiswick Eyot where they were cut off by the rising tide. After the men's race, a greater number of people were in trouble.
In one lifeboat, RNLI helmsman Peter Knight dealt with a large group of people who were trying to reach safety via a small ladder. They were not able to evacuate before the tide rose substantially and many were trying to paddle and stay upright on a very slippery surface.
David Clarke, of the Chiswick RNLI, told the Evening Standard: "They were people on the foreshore just caught out by the rising tide and substantial wash from the flotilla that follows the race.
"They could not get out without swimming."
Meanwhile, Chiswick RNLI Station Manager Wayne Bellamy told Get West London: "This incident showed once more that the tidal Thames can catch people unaware.
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