While Olympic rowers and plucky amateurs did battle along the Thames on Friday, thousands of champagne-fuelled spectators lined the banks to cheer them on at the Henley Royal Regatta.
The sun shone, the Pimms flowed freely, the ladies showed off their hats and dresses and the gentlemen squeezed into old blazers for this annual summer fixture, whose roots stretch back to a maritime past when Britannia ruled the waves.
"It's an international regatta, a national regatta, a place for reunions and anniversaries all rolled into one," said Henley Chairman Mike Sweeney.
Off the water, competitors and spectators must adhere to the strict rules that have traditionally governed the dress and comportment of the British upper classes at play.
Guests and members who are admitted to the Stewards' Enclosure, where there are grandstands, deck chairs, champagne bars and restaurants, must look the part.
"Gentlemen are required to wear lounge suits, or jackets or blazers with flannels, and a tie or cravat," say the instructions on Henley's website.
Many wear their old rowing club blazers: the enclosure is festooned with the tasteful dark and light blues of Oxford and Cambridge, but also a host of garish jackets in every colour of the rainbow - striped, plain and patterned.
"Ladies are required to wear dresses or suits with a hemline below the knee and will not be admitted wearing divided skirts, culottes or trousers of any kind," the website states.
Chancers are told in no uncertain terms that the following items are beyond the pale: jeans, shorts, the use of mobile phones, children and journalists.
Out on the water, Henley favourite and London 2012 Olympic gold medal-winning single sculler Mahe Drysdale from New Zealand lost to rival Aleksandar Aleksandrov from Azerbaijan, while British Olympic bronze medallist Alan Campbell, 30, confessed to nerves after surviving a false start and winning through to the semi-finals.
For top athletes like Drysdale, Campbell, British gold medallist Helen Glover and others competing on Friday, rowing at Henley the year after the Olympics is a chance to have fun, enjoy the rare admiration and roar of a crowd at a non-Olympic rowing event, or restart a training programme.
Drysdale, 34, told Reuters he had had a long layoff since the Olympics and his entry was the opportunity to gauge what he needs to do to get back into shape for Rio in 2016.
"I took that break knowing that I wanted to continue and I'm back in the boat and committed to another four years," he said.
Established in 1839 before international or national rowing associations evolved, Henley abides by its own rules for the sport, but enjoys the recognition of rowing's leading bodies.
Unlike the multi-lane courses at the Olympics, competitors here race only one other boat at a time in knock-out heats along a course of 1 mile and 550 yards, a bit longer than the standard international distance of 2000 metres.
There are 20 events in total, comprising challenges for crews of eight, four, two and single sculls.
A break in competition for lunch is strictly observed, with restaurants, bars and other eateries on site. But Henley's most sought-after invites are to the traditional summer picnics on the grassy car park behind the regatta.
Surrounded by his two daughters, wife, friends and a hamper stuffed with food, Henley stewards' member Nigel White told Reuters he has been coming back since 1979 to see friends from his old university crew, have a family day out and wax nostalgic about the glory days when he rowed here.
"Once you're a member you never give it up."