Moderate to strong northwest winds varied from 10 to 17 knots throughout the day, and shifts up to 30 degrees put a premium on course positioning.
One of the most exciting matches of the day was a dogfight between Ebler, #8 in the world, and Macgregor, #2 in the women's match racing rankings.
"They were close tacking the entire time and Lucy was to leeward, tacked onto starboard a bit too close and there was contact so she got a penalty," said Henry Menin, deputy chief umpire. Macgregor attempted to draw a penalty from Ebler going downwind but he launched a classic defense to her attempt to double jib and Macgregor got her second penalty. "It was all pretty great stuff," Menin said.
For Ebler, sailing the Sonar, the boat used for the open division, was a new challenge. "This is a completely new boat for us," he said. "It is much heavier than boats of similar size like the J/22 or J/80. So far so good, and we have won all races today."
In the women's division, sailed in Elliott 6m, Senfft and Genny Tulloch (USA) sailed a match so close they exchanged leads right down to the finish line.
"I didn't know until they crossed the line who was going to win the match," Menin said. "They were just powering down with some really nice wind with the lead going back and forth."
For many of the sailors it was their first time competing in Sheboygan, home of host Sail Sheboygan.
"We haven't done much freshwater sailing and we are impressed with the shorter chop conditions and with the Elliott 6m," South African skipper Dominique Provoyeur said. "The wind today has been fresh and the Elliott 6m is a very physical boat. We love the challenge and we love Sheboygan. It's a great little town to explore."
The Round Robin concludes tomorrow with the top three advancing to the Semi Finals. The final Semi Final spot is decided following a repechage involving those who finished 4-7 in the Round Robin,
Full results can be viewed here.
ISAF YouTube Channel will show footage from the event.
ISAF Nations Cup
Following on from earlier editions in 1991, 1993 and 1995, the ISAF Nations Cup was successfully re-launched in 2006. The latst edition took place in 2009 with the Grand Final hosted by Porto Alegre in Brazil. In total 60 teams representing 39 MNAs participated in the 2009 ISAF Nations Cup. Eight Regional Finals decided the line up for the Grand Final at the Veleiros do Sul sailing club in Porto Alegre where France repeated their double victory from 2007 to retain the open title skippered by Damien Iehl and the women's title skippered again by Claire Leroy.
The 2011 ISAF Nations Cup Grand Final takes place from 13-18 September and will be hosted by Sheboygan, USA. Sheboygan, situated on the western shoreline of Lake Michigan, 150 mile north of Chicago, is the second US venue to host the ISAF Nations Cup Grand Final, following on from San Francisco in 1995.