the decision to foil upwind is one that was taken very late in the Oracle campaign, but now they are learning fast and can out perform the Kiwis uphill. I'm also hearing that you sail these boats as if they have distinct gears rather than a sliding scale of performance for a given true wind angle. In other words you can't trade a couple of degrees for a few knots it's either pop it up or sail in displacement mode. Typically two of these gears might be 22knots boat speed at 40 degrees true or 30knots boat speed at 48 degrees true, the latter being the filing gear.
