The Battle of Bermuda resumes without fanfare after a five-day break with the America's Cup defender Oracle Team USA needing to break Team New Zealand's unbeaten winning streak.
The challenger has a 3-0 lead after the opening weekend when it made short work of the defender, negating its bonus point and putting up three of the seven points it would need to win the Cup.
Oracle has had the busiest week on the water in its pursuit for more speed, something it will need with winds for Saturday forecast to be in the same 8-12 knot range that appears to favour Team New Zealand.
Cup watchers say the new rules leave both teams with no dramatic single revelations expected, but the advantage will go to the one that has made the most of incremental performance and sailing improvements.
Both teams have been busy with changes to their boats, the group of officials known as the Measurement Committee have been shuttling between both bases, checking issues often raised by one team against its rival.
Chief measurer Ken McAlpine would not tell RNZ what was being checked, but said their regular visits were normal for this phase of the competition.
No formal protests had been lodged so far, and under another new rule each team is allowed only one unsuccessful protest in the Match on a matter relating to boat compliance.
Oracle Team USA has released a video showing it working on improvements during this week:
Oracle's event arm will be hoping for a comeback, its chief executive Sir Russell Coutts told the German magazine, The Yacht, "So far it's been rather one-sided."
America's Cup Event Authority is charging $US50 a head for a single adult admission to the cup village for this possibly deciding weekend.
Saturday is sold out.