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:
More top news
A clear night tonight and staying dry. Sunday will remain dry with sunny spells.
A new flag of Northamptonshire has been raised at County Hall in Northampton this morning, the design chosen via a public vote.
Police Chief Constable Colette Paul has raised over £300 in memory of former colleague.