The biggest movers on day four of the regatta were busy Nacra 17 pair Jason Saunders and Gemma Jones, who climbed from 13th to fourth.
After finishing outside the top eight in their first two races on Wednesday, Jones and Saunders were seventh, fifth, fourth and second to be on 27 points and 10 points behind co-leaders Australia and Great Britain.
Josh Junior also enjoyed his best day in the Finn class, improving five places to 15th overall courtesy of a fifth and a third.
Junior has four remaining races in which to qualify for the medal race in a class still being dominated by British world champion Giles Scott.
Moving in the other direction was men's 470 crew Paul Snow-Hansen and Dan Willcox, who slumped from third to 11th overall. Poor starts proved costly as they placed 20th and 15th.
It was a reserve day for seventh-placed Laser sailor Sam Meech while two Kiwi combinations will begin their competition on Friday - 49er world champions Peter Burling and Blair Tuke, and 49erFX women Alex Maloney and Molly Meech.