Nearly two thousand people took part in the Great East swim - among them two Olympic swimmers who are hoping to go for gold in the open water events at London 2012.
Russell Hookey spent the day at Alton Water near Ipswich and saw the action:
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Bright or sunny spells to start the day, with occasional showers likely by afternoon
Showers will ease this evening, taking us into a dry night ahead. Generally dry with sunny spells to start tomorrow. Cloud increasing later
The Clacton MP Douglas Carswell was booed during PMQs today as he tried to thank the Prime Minister.