Robertson's crew will battle it out with Sarah Ayton's team

Sarah Ayton, Sarah Webb and Pippa Wilson lead the women's keelboat class by just one point from Annie Lush, Shirley Robertson and Lucy Macgregor.

Ayton, Webb and Robertson won Yngling gold at the Athens Olympics but are in opposing crews in Portugal.

Robertson closed the gap from 11 points to one in Tuesday's two races with just Wednesday's medal race to go.

A third British crew, containing Victoria Rawlinson, Emma Rawlinson and Sue Monson also secured a place in the 10-boat double points-scoring medal race.

Ed Wright has improved his position heading into the final day of a fiercely competitive Finn class.

The 2006 world bronze medallist is in fourth place, just two points off the gold medal position.

European champion Paul Goodison finished fifth in the Laser class while Charlotte Dobson was 10th in the Laser Radial event.

Stevie Morrison and Ben Rhodes are seven points clear at the top of the 49er class while defending world champions Chris Draper and Simon Hiscocks have moved up to 10th.

Nick Rogers and Joe Glanfield improved to second overall in the men's 470 category with Christina Bassadone and Saskia Clark gaining three places to go third.