London 2012 sailing 'rehearsal' at Weymouth and Portland
Racing has begun at a sailing event in Dorset in an event acting as a "dry run" ahead of the London 2012 sailing competitions next July.
The Weymouth and Portland International Regatta has sailors from 60 nations taking part, while Olympic organisers check how the venue operates.
It aims to replicate the conditions expected at next year's Games.
The Weymouth and Portland National Sailing Academy will host the sailing events for the 2012 Olympics.
A total of 170 races will be held in this year's competition, which runs until 13 August.
Organisers London 2012 Organising Committee (Locog) and ISAF (International Sailing Federation) have said the Regatta would test the venue, systems, equipment, workforce and procedures.
Alastair Fox, from the ISAF, said: "The Olympic Test Event offers a great opportunity for sailors, coaches and support staff from nations around the world to experience the sailing conditions and gain an understanding of the venue."