Westerhof and Berkhout lead Tara Pacheco and Berta Betanzos (ESP) in second. French pair Camille Lecointre and Mathilde Géron climbed to third after a fourth and a first.
Different skill sets were tested on the water today but for Mathew Belcher and Malcolm Page (AUS) they remain in control and continue to lead the Men's 470 fleet over the Dutch Coster brothers and Greece's Panagiotis Mantis and Pavlos Kagialis.
"In race one we did quite well and got a nice shift to the right, it was really fickle and nobody had any real idea where to go, you just had to use the opportunity in front of you and hope for the best a bit, things went our way and we finished fourth," said Belcher. "We found ourselves pretty deep in race two but fought our way back from about 25th or worse at one point to finish 11th which was fantastic."
With two second place finishes in today's racing, Portugal's Marinho Alvaro and Miguel Nunes climbed to fifth. Gold fleet race victories were taken by the Japanese duo Ryunosuke Harada and Yugo Yoshida and Finland's Joonas and Niklas Lindgren.
Tom Slingsby (AUS) proved his worth in the Laser today to place second twice in the light air. The World #1 sailor leads from Germany's Phillip Buhl and Andy Maloney (NZL). "It's been so close all week so it was good to finally get some points separation today," said Slingsby. "I had two seconds today and it was a real drag race to the right in both races, I was lucky in race one as I had a bad start and had to tack out to the right anyway and then in race two I got to the right when I wanted."
In the first day of gold fleet racing Marit Bouwmeester (NED) showed why she is the 2011 World Champion after bouncing back from a 15th in Race 7 to fourth in Race 8 which subsequently handed her the lead. Alison Young (GBR) drops to second behind the Dutch sailor and Lijia Xu (CHN) is third.
Piotr Myszka (POL) keeps his first place in the Men's RS:X with another consistent day on the water, but the day's conditions suited his team mate Lukaz Grodzicki (POL) who claimed both races. Shahar Zubari (ISR) climbs to second with Toni Wilhem (GER) in third on equal points with Przemek Miarczynski (POL).
For Maja Dziarnowska (POL) the day was not ideal, the young Pole suffered from the tricky conditions placing 15th and 20th in the Women's RS:X. She concedes her lead to France's Charline Picon (FRA) who raced to perfection with two victories.
With a near perfect day that included two bullets and a fourth place, Australia's Nathan Outteridge and Iain Jensen (AUS) have climbed to the top of the leader board on 28 points. They sit tied with Manu Dyen and Stephane Christidis (FRA) whose results weren't as flattering as their five top four finishes in the previous six races in big winds. Peter Kruger Andersen and Nicolai Thorsell round off the podium on 35 points.
Deniss Karpak (EST) suffered in the light winds today and loses his grip on the Finn leader board. Following three bullets in the big winds Karpak could only managed a 10-12 scorecard on day four. Proving to be the most consistent is Rafa Trujillo (ESP). The Spaniard went 1-2 to move into the lead on 12 points.
In the Star class Iain Percy and Andrew Simpson (GBR) top the leader board on 14 points followed by Richard Clark and Tyler Bjorn (CAN) on 18 points and Fredrik Look and Max Salminen (SWE) on 20 points.
And in the Women's Match Racing, Anna Tunnicliffe (USA) marches on with a 100% record. The Round Robin will conclude tomorrow before they head into the finals stage. And with Tunnicliffe on form she will be the one to beat.
Damien Seguin (FRA) leads the 2.4mR on 10 points, John Robertson, Hannah Stodel and Steve Thomas (GBR) have a 2 point advantage at the top of the leader board in the Sonar and with four race wins Dan Fitzgibbon and Liesl Tesch (AUS) are in control in the SKUD.
It will be an early start for the Women's Match Racers tomorrow with racing scheduled to start at 08:30 local time. The rest of the fleets will commence at 10:00 with the Medal Race places set to be decided.