Fast starts are key, race tactics and weather conditions will all play their part, but it could be human effort which determines who wins the America’s Cup.
Each boat has eight crew members, reduced from 11 last time, with two helmsmen and two sail trimmers on different sides.
Joining Ainslie as co-helm will be Olympic gold medallist Dylan Fletcher, who won the 49er class at Tokyo 2020, while Leigh McMillan and Bleddyn Mon are the trimmers.
The other four sailors on the boat provide the hydraulic power to trim the sails by pedalling static bikes fixed inside the hull.
Four of the nine “cycling sailors” in the Britannia squad have an Olympic rowing background – including 2016 gold medallist Matt Gotrel and Tokyo silver medallist Harry Leask.
Known as “cyclors”, they have been put through their paces on dry land by Grenadiers’ top cyclists to build their endurance levels.
Double Olympic gold medallist Giles Scott is the team’s head of sailing.
There is also a big onshore team including sailmakers, engineers, software technicians and even meteorologists.
It is estimated that the average America’s Cup campaign costs about £100m.