If racing in the Louis Vuitton challenger series is postponed today, teams will race twice tomorrow.
For the third day in a row light winds disrupted racing yesterday, causing a headache for organisers.
With similar weather predicted until tomorrow, the Challenger of Record Management Committee consulted the challengers overdoubling up.
For each round robin there are five reserve days. One is in the middle of racing and four are tagged on at the end.
Seven "off days" are scheduled between the two round robins, from October 15-21, which will not be used as race days because they are set aside for syndicates to modify their boats if they choose.
The first round robin was scheduled to finish today, with reserve days from tomorrow to Monday.
But there are three flights left to sail, plus two races that were postponed on Monday and three races that were postponed on Tuesday.
"If we lose Thursday, we'll start to double up on Friday. Otherwise we will have to double up on Saturday," said Dyer Jones, the regatta director for the management committee.
If teams are forced to race twice a day it will be on shorter courses, with the first race starting at 10.30am.
In the one-hour break between races, teams would be able to change the crew and sails.
Oracle BMW Racing tactician John Cutler said that with a sailing squad of 36, racing twice a day shouldn't pose too much of a problem for his team.
"We have got a rotation that we are working through now anyway.
"We would just continue with that, so I think we are well equipped to handle two races a day."
If races in the first round robin are not completed by Monday evening the remaining races will be sailed at the start of round robin two, when syndicates have the option of sailing with modified or different boats.
Race organisers have forecast light variable winds until tomorrow and then, ironically, gusts of 35 knots for Saturday.
For challenger series racing the wind speed must average between seven and 19 knots, and not exceed 23 knots during the race.
Today's draw, which is the same as yesterday's, sees OneWorld up against Victory Challenge and GBR against Prada on Course Romeo, while on Course Juliet, Alinghi face Team Dennis Conner and Le Defi Areva meet Oracle BMW Racing.
