The International Jury has started hearing the protests from Emirates Team New Zealand and Luna Rossa Challenge about the proposed changes to their America's Cup boats.
The two cases have been consolidated and will heard together with parties being given the opportunity to speak to their submissions.
Both Emirates Team New Zealand and Luna Rossa are arguing Regatta Director Iain Murray exceeded his authority when some of his 37 Safety Rules effectively changed the AC72 Class Rule.
The Regatta Director argues the changes are necessary to run a safe regatta and are in line with the Rules of the event.
International Jury chairman David Tillett says they'd like to have a decision on Thursday (NZ time).
Luna Rossa didn't race Team New Zealand, saying they would not compete until the case had been heard.