More than 250,000 people are expected to attend this year's Henley Royal Regatta which begins on Wednesday.
Organisers expect about 30,000 people to attend the opening day
The annual rowing competition takes place over a stretch of the Thames, just under a mile-and-a-half in length, on the Berkshire/Oxfordshire border.
This year's event has attracted 470 crews from 19 countries including many teams who are using the event as a warm-up for the Athens Olympics.
The regatta runs from Wednesday, 30 June, to Sunday 4 July.
Organisers are expecting more than 30,000 people to gather at the banks of the river for the opening day.
Mike Sweeney, of the organising committee, said: "I am very pleased that we have been able to attract a number of Olympic crews to this year's regatta and, in particular, that the British Olympic team is so well-represented.
"This is a wonderful opportunity for the British rowing Public to see their Olympic competitors in action for the last time before they set off for Athens."
Henley Regatta was first held in 1839 and has been held annually ever since, except during the two World Wars.