Rickham and Birrell missed out on gold in Miami - the second leg of the World Cup series - by just one point to the Australian duo of Daniel Fitzgibbon and Liesl Tesch, but helm Rickham insists they were happy with their performance at a venue which has proved tough for them in the past.
She said: "We're happy with everything - this is pretty much the worst venue for us. We seem to suffer here every year so to come away with a silver is quite a big step forwards.
"We just missed out on the gold, normally we're fighting just to get the bronze so we leave here really confident and happy with our winter's work."
Gold in the Sonar event went to the Dutch trio with Robertson, Stodel and Thomas five points behind after the 10-race series. The 2.4mR Paralympic class also concluded racing with Skandia Team GBR's Megan Pascoe finishing fourth and Helena Lucas fifth.
After a near-flawless week in which he counts only race wins on his scorecard, Nick Dempsey has almost assured himself of gold in the RS:X men's windsurfing event.
The Athens bronze medallist and 2009 world champion has amassed an 18-point lead going into the 10-boat double points-scoring finale.
The women's match racing trio of Lucy Macgregor, Annie Lush and Kate Macgregor also guaranteed themselves at least a silver medal when they overcame Finland's Silja Lehtinen in their nail-biting semi-final.
Gold in the Laser class will be a straight duel between Olympic champion Paul Goodison, and the Brazilian Bruno Fontes who are both tied on points going into the final day.
But things are less clear cut in the 470 women's event. The British pair are now 12 points off of the gold medal spot and are one of three teams who could win silver.