Wales's Hannah Mills and Saskia Clark were beaten to 470 class gold after a disappointing final day at the Olympic test event in Weymouth.
The pair led by a point going into Friday's last medal race but could only finish fourth.
Their nearest rivals, Japan's Ai Kondo and Wakako Tabata, were second, which meant they secured gold ahead of their British opponents.
Englishman Paul Goodison took bronze in the Laser class.
Clark was sixth at the 2008 Olympics and this is her first season with Mills, who replaced Sarah Ayton.
But she was disappointed not to have emerged victorious at the 2012 Olympic venue.
"We are pretty gutted not to take gold but I'm sure that in a few hours I will be happy." she said.
"We wanted to win our first regatta together, but obviously that hasn't happened.
"Expectations rise and you want to deliver on that. We are going to do all we can to not be in this position next year."
Mills added: "It was close and we were always catching up, putting on pressure. But it didn't quite come off in the last leg and it is all a bit disappointing really.
"We had a couple of unlucky shifts but overall we did a good job."
Goodison, who won gold in Beijing, could not finish worse than fourth in his category going into the medal race, which he won, to earn bronze.
"I am a little bit relieved and a little bit disappointed," said the 33-year-old.
"When there is a chance of winning heading to the final race you always want to win the gold.
"When there is a chance of finishing first, second, third and fourth, finishing third is probably only halfway.
"So I am a little bit disappointed but happy to have medalled again here in Weymouth."