Ben Ainslie and the Ineos Britannia crew are making a remarkable bid for a comeback in the 37th America’s Cup. After facing a daunting 4-0 deficit against Emirates Team New Zealand in the best-of-13 series, the British team has rallied to narrow the score to 4-2. The shift in momentum came with a change in sea conditions off Barcelona, which favored Ineos Britannia. The America’s Cup is not just a test of sailing skill but also of boat design, and the subtle differences between the two AC75 yachts played a crucial role. In heavier weather, the British team found an advantage that allowed them to regain their footing in the competition. New Zealand's initial success was largely due to their boat, Tahoro, being optimized for calm waters. Their design features “dry bulbs” on the foil arm, which helps meet weight requirements while reducing the surface area in contact with the water. This design proved effective in flat conditions but became a liability as the waves picked up, allowing Ineos Britannia to capitalize on the changing circumstances. With the score now at 4-2, the stage is set for a thrilling continuation of the series as Ainslie and his crew aim to complete their comeback.