Looks fun! More details here: www.redbullairrace.com
The Port of London Authority Notice to Mariners
says "Because of the nature of the activity, no craft, unless part of the Red Bull Safety Team will be permitted to remain within the exclusion zones whilst flying is taking place."
However, the chart of the exclusion zone
shows a fair bit of space on the river to the north of the exclusion zone which might be a good place to head for.
HW in the race areas is around 1330 on Saturday, 1400 on Sunday, which should work OK for finding somewhere to moor up to.