"Half way through the series it was acknowledged that Oracle had fitted an automatic control to their hydrofoil trim, and that this modification was approved by the measurement authorities."
"The 'legality' of this device has been justified and accepted on the basis that it does not actually 'drive' the trim of the foils.....this is still performed by the muscle power of the crew, via hydraulic linkages."
"The Racing Rules on the matter are very clear RRS42 Propulsion states: A yacht shall compete only by using the wind and water to increase, maintain or decrease her speed. Her crew may adjust the trim of the wing, sails, rudders, daggerboards and hulls, and perform other acts of seamanship."
"The vital words are at the opening of the second sentence 'her crew' - meaning that an automated adjustment which works independently of crew intervention is illegal."
"Even under the current America's Cup rules such a system is quite legal, and it is hard not to believe that such systems were not used again in the 2013 America's Cup. The key point being that there must be a crew intervention between the computer and the sail or other control named in RRS42."
The "stability augmentation system" has been public knowledge since August 8. Here's the schematic: AC 34 Measurement Committee Public Interpretation 49 ETNZ protested the measurement committee's interpretation in early September, but the jury ruled the protest invalid because ETNZ filed too late (they had 14 days to file). In an unusual move, the jury opined in that decision that they would not have ruled in ETNZ's favor anyway.
