The crew has found replacement blades and hopes to have them in Panama by Wednesday, when Earthrace is scheduled to arrive.
The boat set off at a brisk clip from Barbados, zipping along at about 25 mph and heading toward Panama, about 1,440 miles away.
At the end of the first day, Bethune said Earthrace had traveled 621 statute miles, about 235 miles ahead of where a boat named Cable & Wireless was in 1998 at the start of its successful record bid.
On Monday, Bethune and his crew were nursing Earthrace along at less than half that speed, hoping the propellers would stay together long enough to get to Panama.
"We're going so slowly that in another couple of days we'll be well behind the old record time," Bethune said. "Right now, the priority is to just get safely in to port. We are concerned these blades will come to bits before we make it."
The boat's all-volunteer ground crew is scrambling to get equipment in place in Panama to change out Earthrace's propellers, said marine engineer Scott Fratcher.
"If we can have the entire prop changing equipment on hand when Earthrace arrives we can possibly change the props in four hours while we fuel," he wrote in the project's Weblog. "Earthrace could be on her way straight away."
