Canoe slalom gold medallists Etienne Stott and Tim Baillie are making an appearance at the Lee Valley White Water Centre.
The centre is the first London 2012 venue to open to the public after the Games.
Plans have been unveiled for a £4.5 million development of the centre starting in January 2013.
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It's not just London where elections have been taking place today. There were council elections taking place across the home counties.
A list of results for London Mayor and the London Assembly
They said they wouldn't do it. But the Met Police couldn't resist the challenge set by their colleagues in Scotland.