GB's Gimson & Burnet miss out after disqualificationpublished at 12:12 8 August
British duo John Gimson and Anna Burnet's hopes of claiming a medal in the mixed multihull event came to a crushing end when they were disqualified in the final race.
Gimson and Burnet - Olympic silver medallists in Tokyo - were third heading into the double-points medal race.
However, they were judged to have crossed the line before the starting horn sounded and forced to retire while their competitors continued.
The couple, who are planning to get married after the Games, received the maximum 22 points which saw them move down to fourth in the overall standings.
"We made one mistake and it's cost us an Olympic medal so you can imagine we're pretty broken," Gimson said.
Burnet added: "In that moment it's devastating, it's a bad dream but we can be proud of what we have done.
"There's no-one I'd rather be here with. We're so lucky we get to do this together. The highs and lows, we're biding it together."
Italy's Ruggero Tita and Caterina Banti, who led going into the medal race, crossed the finish line in second to retain their Olympic title.
Mateo Majdalani and Eugenia Bosco of Argentina took silver, while New Zealand's Micah Wilkinson and Erica Dawson won bronze.
Earlier on Thursday, Austria's Vadlau and Lukas Maehr were crowned Olympic champions in the mixed dinghy event.
Japan's Keiju Okada and Miho Yoshioka stayed near the front of the pack throughout in the double-points finale to secure silver, while Anton Dahlberg and Lovisa Karlsson of Sweden picked up bronze.