Boats muster on the Thames.
These vessels will sail as part of the biggest river pageant London has seen for 350 years.
It's part of celebations of Queen Elizabeth's Diamond Jubilee.
Pageant Master Adrian Evans says they've been preparing for two and a half years.
(SOUNDBITE) (English) PAGEANT MASTER ADRIAN EVANS, SAYING:
"Finally, today is pageant day. All these vessels - all the vessel owners are thrilled and excited and getting ready for their voyage down the Thames this afternoon."
A thousand boats of all shapes and sizes will sail in the flotilla from Chelsea to London's Tower Bridge.
The Queen will ride on the Spirit of Chartwell, a luxury cruiser turned royal barge.
Lindsey Parietti, Reuters
