Two British crews assured themselves of at least silver medals at Weymouth Bay but hopes of a bronze evaporated in the only class to hold its medal decider yesterday.
Hannah Mills and Saskia Clark, making their women's division pairing debut, are lying on equal points with New Zealand's Jo Aleh and Olivia Powrie.
Both teams are sufficiently well clear of the Dutch crew of Lisa Westerhof and Lobke Berkhout to make the race-off tomorrow a head-to-head affair.
Luke Patience and Stuart Bithell had already done enough by Tuesday to make sure they had the silver in the 470 dinghy class. They have to beat the Australians Mathew Belcher and Malcolm Page, the runaway favourites, by two places to take gold.
The women's crew do not have the slightest intention of settling for silver. "No," said Clark, "we want to win, we definitely want to win. We've got this far. We want to close it out."
Mills added: "We've got a great chance of winning gold, so we'll see what Friday brings."
She explained that as part of their training programme they had done two or three days of match racing, and were quite prepared to "sit" on their opponents and block them all the way to the finish if it became necessary.
That is, assuming that the weather does not interfere for the first time in a race schedule that has run miraculously smoothly so far.
Conditions have been changing from fresh to lighter breezes, but if the track is too soft and soggy to race today both races would be staged tomorrow.
The softer conditions would definitely suit the British women more than the Kiwis.
For Stevie Morrison and Ben Rhodes it is back to the drawing board in the 49er skiff. The gold had already been bagged by Australia's Nathan Outteridge and Iain Jensen, the silver by their training partners Peter Burling and Blair Tuke of New Zealand. The Britons had been pushed hard for selection by John Pink and Rick Peacock but "we haven't won a medal because we weren't good enough, we haven't won a medal because we made a few mistakes," said Morrison. ""We've really caught up."
The bronze went to Denmark's Allan Norregaard and Peter Lang.
The British women's match race trio of Lucy Macgregor, Annie Lush and Kate Macgregor were beaten 3-2 by Russia in the quarter-finals.