The rare sight of a pod of dolphins swimming down the Thames delighting surprised onlookers on Friday.
The five cetaceans were first spotted near Tower Bridge by the Met Police's river boat Marine 2, before heading up river to Battersea Power Station where they caught the eye of walkers and cyclists.
Thursday night's storm could be the reason behind the dolphins' Thames adventure as strong winds caused high tides around Britain's coastline.
Stephen Mowat, marine conservationist at the Zoological Society of London, said: "They may be further up the Thames than usual as they are following prey-fish on the particularly high-tides in the storm surge conditions."
"Although Harbour porpoises are more common in coastal areas around the UK they are occasionally reported in the River Thames through our marine mammal sightings project."
But it was not the first time a sea mammal has swum into the Thames, in February a harbour porpoise was seen in the river near Putney Bridge.
Sadly the discovery was spoiled by an horrendous pun tweeted by Sea Life London.
It read: "Look who @TowerRNLI spotted splashing about in the #Thames today. Good to see our river is 'fit for #porpoise'."
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