The Bird 's Nest is back in action with Britain 's Daniel Awde in his first decathlon events ( from 0220 ) , Johanna Jackson competes in the women 's 20km walk ( from 0200 and hopefully as brutally contested as the 10km open water swimming ) , Tonia Couch and Stacie Powell have made it through to their diving semi-finals in the Water Cube ( from 0300 ) , and GB duo Sam Weale and Nick Woodbridge are in the men 's modern pentathlon - their first event has just started .