KEY POINTS:
The challengers have been wrapped up in the Louis Vuitton Cup, but the intrigue continues over whether a team have improved the performance of their keel which could give a crucial speed edge.
Another series of questions to the measurer was recently made public relating to the keel and preventing of fin deflection, which occurs due to the weight of the 19 tonne keel bulb.
The questions are at least the fourth lot over the last 18 months relating to the same issue. And, as with nearly all of the questions, the measurer's answers were again no.
Desafio Espanol's technical director and tactician John Cutler said it was interesting.
"It has been going on for a year and a half now that someone has been asking these questions about can you have a canting keel? Can you have a structure that performs in a positive way? Can you somehow link the loads to the keel that will somehow make the boat go better?"
The questions and the answers are made public, the person or team that asked the questions is not. Measurer Ken McAlpine can ask and answer questions himself if he feels something needs clarifying.
There is no evidence to prove it but many suspect that if anyone has engineered a breakthrough it is defenders Alinghi.
So one or more of the challengers may be constantly questioning the measurer to ensure that if Alinghi are doing something it is legal.
"I am completely guessing but I assume Oracle sent the last lot of questions," Cutler said.
"They are taking it a lot more serious now that those guys [Alinghi] could be doing it ... Oracle and Luna Rossa are perhaps the ones most concerned about it."
Alinghi's general counsel New Zealander Hamish Ross used the example of Team New Zealand's hull appendage in the last cup.
Ross told Swiss newspaper Le Temps that in the last cup they were "non-stop submitting questions to the technical committee to work out at which point it was legal".
He pointed out that sometimes what was regarded as innovation by a team was often seen as cheating by their rivals.