There were no changes at the very top of the leaderboards in any of the fleets at the end of the day, with Ricardo Santos of Brazil leading the men's RS:X, Blanca Manchon (ESP) heading the women's RS:X and the Australian pair of Nathan Outteridge and Iain Jensen at the head of the 49er fleet.
Racing was delayed by two hours until 13.00, when the men's RS:X sailors were the first to take to the water in winds of 22 knots gusting up to 28.
Santos continued to thrive in the wind, winning the first race of the day. But it was his great friend João Rodrigues from Portugal, who took the honours in the second race. He got his tactics spot on to win by a proverbial country mile.
Santos was overtaken by France's Alexandre Guyader close to the finishing line and had to settle for third place.
An elated Rodrigues said, "I was really lucky in the last upwind. I was the only one going to the right, everyone else went to the left. I finished with a big lead - it happens sometimes."
But Rodrigues is still tipping Santos, nicknamed Bimba, to take the title at this year's Skandia Sail for Gold Regatta.
"It's going to be pretty close between the top five, except for Bimba. He's already got a pretty big lead in a pretty small fleet. But for the rest of us it's going to be an interesting fight. We've been swapping places since the first day."
And the Portuguese windsurfer said he's enjoying the challenging conditions at Weymouth and Portland. "The conditions have been perfect," he said. "It's incredible, it doesn't stop blowing. It's been great so far."
Santos now has nine points, with Julien Bontemps (FRA) on 14, and with both Rodrigues and Guyader on 15, and Nikolas Kaklamanakis (GRE), who had led the class at the end of day one, now fifth. Richard Hamilton is the highest placed Brit in eighth on 43 points.
Skandia Team GBR's Bryony Shaw closed the gap on Spain's Manchon by winning the first women's RS:X race of the day. That victory - her first of the regatta - put the Beijing 2008 Olympic bronze medallist just five points behind Manchon, who finished second.
But Manchon fought back to win the second race - her fourth victory out of the six races contested to date. Italy's Flavia Tartaglini came second, with Shaw crossing the line in fifth.
Shaw maintains her second place in the overall rankings on 15 points - nine behind Manchon. Tartaglini is third on 17.
Shaw said, "The first race today was a real breakthrough because the Spanish girl is going very quickly. I managed to pull away from her every downwind leg and maintain my lead.
"My confidence took quite a knock by not medalling at the World Championships, so this was a good confidence builder. I was really chuffed.
"I think I over complicated the second race a bit, trying to make gains that maybe weren't there. But that was a good learner," she added. "There's such an awesome fleet of girls here that I'm trying to learn from every scenario."
The 49ers sat out the racing yesterday but returned to action this afternoon in winds of 23 knots gusting to 30.
The Australian pair of Outteridge and Jensen consolidated their position at the top of the fleet by winning the first race of the day and then finishing second, although they could only manage 17th in the final race.
Outteridge said, "We had a pretty good go today, but we had a swim in the last race. Hopefully that will be our drop. It should be pretty close by the end of the regatta.
"It was definitely a very tough day, but good for us to get a bit of practice in the breeze," he added.
Britain's Stevie Morrison and Ben Rhodes, who won last year's Skandia Sail for Gold Regatta, had their best finish of the regatta, coming second in the opening race and ended the day in fifth overall.
The Italian Sibello brothers - Pietro Sibello and Gianfranco Sibello - stormed up from 20th at the start of the day to end the day in fourth, finishing fifth in the first race, winning the second and coming third in the final race of the day.
"Before we went out today we were a bit scared because of the conditions, but in the end it was a really good day," said Pietro Sibello. "The wind was strong, but it was still good for racing and I think we had three good races."
The Spanish crew of Iker Martinez and Xabier Fernandez won the last race of the day to climb to sixth. Britain's Chris Draper and Peter Greenhalgh finished second in the last race to end the day in seventh.
The action continues on Thursday through until the Medal Races in Weymouth this Saturday.
ISAF Sailing World Cup
The ISAF Sailing World Cup 2008-2009 consists of the following events:
16-21 Dec 2008 - Sail Melbourne The Asia Pacific Regatta, Melbourne, Australia
25-31 Jan 2009 - US SAILING's Rolex Miami OCR, Miami, USA
4-10 April 2009 - Trofeo SAR Princess Sofia MAPFRE, Palma, Spain
18-24 April 2009 - Semaine Olympique Francaise, Hyeres, France
27-31 May 2009 - Delta Lloyd Regatta, Medemblik, Netherlands
20-28 June 2009 - Kieler Woche, Kiel, Germany
14-19 Sept 2009 - Skandia Sail for Gold Regatta, Weymouth, Great Britain
Find out more about the ISAF Sailing World Cup, including the World Cup Standings, more on the seven events, the scoring system and the Notice of Series at www.sailing.org/isafsailingworldcup.