The early sea state was testing for the fleet, with two boats breaking masts, one in the 49er class and the other a 470.
"It was very tough", said Oliver Tweddell, winner of both races in the Finn class. "Big waves, a lot of wind and some seriously big shifts. It was a day that kept us on our toes, that's for sure," he added.
"The breeze had been coming from the west since early this morning and the wave size picks up really quickly on Port Phillip. There were a lot of rain clouds coming through, bringing a lot of breeze with them and they just kept feeding the breeze all day," Tweddell explained.
There was close racing at the head of the Finn fleet with Tweddell fending off 2012 Olympic representative, Brendan Casey (AUS), by just a boat length in the two races sailed.
After one drop, 20 year old Jake Lilley continues to lead the Finn class. The 2 metre (6' 7") Finn sailor, who came out of elite junior triathlon and cycling, has been just one year in the Olympic Heavweight dinghy. "It was a tricky day today, with plenty of bump," he said. "There were 30 degree shifts and big waves, so it was a lot of fun."
Surprisingly the big-framed Lilley did not thrive in today's conditions placing fourth and fifth in the two races sailed.
Equal on points, after a pair of thirds, is Bjorn Allansson (SWE), who was ranked #3 in the world back in April and is in good form. ''Today I sailed really good upwind, but was having trouble getting a flow on the downwind legs and Tweddell sailed through us."
Matthew Belcher and Will Ryan (AUS) continued their march towards 18 consecutive regatta wins, with two wins from today's racing.
"We had good conditions for the 470's today," said Belcher. "Great racing, we had two good starts and two good results."
Their rivals, Sime Fantela and Igor Marenic (CRO) lacked the dominance of the Australians finishing with second and third places from the two races sailed.
"We could have done a little bit better in the last one", said Igor Marenic. "The wind was really strong with big waves, we were struggling a little in the big waves. We needed to find good trimming. But all in all, the regatta is going very well, we are close to the Australians.
"We were on our last gear, we had winds gusting 20 sometimes a little more. A nice breeze, and we enjoy the surfing on the big waves. It was good sailing."
The Brazilian team were tested by the challenging conditions; skipper, Geison Mendes said of their performance, "It is difficult for us with the big waves. We have to train more in these conditions, with the strong winds."
The Chinese team of Shasha Chen and Yang Gao are dominating the women's 470 with five wins from six races. They hold a ten point lead over Australian Youth World Champion Carrie Smith sailing with former rower Sarah Cook. Smith and Cook posted two fourth place finishes and sit one point ahead of Jacqueline Gurr and Amelia Catt.
Only one race was sailed in the 49er and 49erFX with the Olympic skiffs struggling in the fresh winds and sea state that saw only six boats finish the race. Four races are scheduled tomorrow starting at 11.00.
Nathan Outteridge and Iain Jensen won the fourth race and posted their third win of the series. The young New Zealand crew of Logan Dunning-Beck and Jack Simpson did their regatta chances no harm, with a fourth place lifting them to fourth place overall in the regatta.
The new British pairing of Stevie Morrison and Chris Grube were the last recorded finisher and lie in seventh place overall. Morrison is a former world champion in the class and double Olympic representative. Grube comes to the 49er from the 470 class, with some notable performances in the build up for the 2012 Olympics in Weymouth.
The Norwegian crew of Ragna and Maia Agerup enjoy a six-point lead at the top of the points table after just one race was sailed today, in which they placed third.
The 18year old twins started sailing at the age of eight in the Optimist, 29er and now 49erFX. They are the youngest crew in the class at Melbourne and placed 26th at the only World Championship sailed to date for the new 49erFX class.
Second overall is the Australian crew of Olivia Price and Eliza Solly, who won the day's only race. Price was a Silver medallist in the Women's Match Racing event at the 2012 London Olympics and placed ninth overall in the 49erFX Worlds sailed at Marseille, France in September this year.
Hayley Outteridge, sister of 49er Gold Medallist, Nathan Outteridge, suffered a knee injury in today's racing and had to be assisted from the course aboard a support vessel.
Tom Burton (AUS) continued his stream of success notching his fourth win in six races and has established an eight point lead over compatriot Ashley Brunning; with Thomas Saunders a further three points back.
Both Brunning and Burton filed their worst placings of the today, with Burton finishing fourth in the first race of the day. Brunning seemed determined not be outdone and placed sixth in the final race of the day. Saunders was more consistent placing second and third.
Tatiana Drozdovskaya (BLR) is easing away to a big lead in the women's one person dinghy, scoring a fourth and first placing in the day's races. The Belarusian is enjoying a run of recent success having finished second at the previous ISAF World sailing Cup event in Qingdao, China.
Krystal Weir, who placed 12th in the 2012 Olympics and won the 2012 ISAF Sailing World Cup Melbourne, scored two second placings to sit in second place overall ahead of Qingdao gold medallist Dongshuang Zhang (CHN).
There is a tie on the top of the points table in the Nacra 17 event. With New Zealand's Gemma Jones and Jason Saunders scoring two wins from three races. They would have made it a hat-trick but for a rudder popping up 200 metres from the finish whilst leading and the subsequent capsize dropped them back to seventh place.
"We had a nice breeze with good waves," said Jones. "But it was really shifty out there. We won the first two races, which was good considering the shifty conditions. In the last one we were leading, but the rudder popped up and we capsized, so it didn't end as well as we hoped. But it was still a good day.
"We had good starts and good speed, particularly downwind, which helped as well.
"We were completely comfortable in the conditions which made it easier to win, I guess. We overlaid a few marks in the first race, which made the racing closer than we would have liked."
"I really enjoy the Nacra. I guess it suits my type of sailing. The new rig has made the boat more fun. The loads are a little heavier on the mainsheet, but it helps downwind and you don't nosedive so much."
One of those crews is Olympic Silver Medallists Darren Bundock and Nina Curtis, who are laying second overall in their first Nacra 17 regatta.
"The Kiwis went for a swim in the last downwind which was nice of the them," Bundock quipped after racing. "It's taken us a little while to get going. But we are steadily improving, by the last race today, we were very happy with our speed," he added.
The men's RS:X fleet completed another three races two of which were won by overall leader Chuankun Shi (CHN). The consistent Chunzhang Liu (CHN) sits five points adrift in second overall and Australia's Patrick Vos to claimed the first race win of the day is third.
In the women's fleet the Chinese are dominant holding all of the top five places. Three race wins for Manjia Zheng secures her first overall with a five point lead over Qiaoshan Weng. ISAF Sailing World Cup Qingdao gold medallist Peina Chen had her best finish so far in race 4 and lies third overall.
Paralympic Classes - SKUD and 2.4mR
Racing was abandoned for the Paralympic classes due to the sea-state on Port Phillip.