Ellen MacArthur's giant catamaran Kingfisher 2 collided with a submerged object in the Southern Ocean on Tuesday evening but suffered minimal damage.
Kingfisher needed repair work after the crash
MacArthur was on day 21 of her bid to break the Jules Verne record for sailing non-stop around the world when the drama occurred south of the Cape of Good Hope.
"During the night suddenly there was a load bang, and the boat shuddered. We had hit something with the starboard rudder," said MacArthur.
"We slowed the boat down to check, and we've a little repair to do on the fixings but it
appears not to be a major problem, thankfully.
First thoughts are, you could be sinking here
Kingfisher 2's Neal McDonald
"We don't know what it was but hitting any object at speed is always a concern."
Watch leader Neal McDonald added: "First thoughts are, you could be sinking here
- a major concern, but we ascertained that we weren't and then checked the whole
boat for damage.
"In retrospect we were very lucky."
MacArthur, 26, and her 13-strong team are trying to break the record of just over 64 days, set by Frenchman Bruno Peyron on Orange last May.
At 0700 GMT on Wednesday, Kingfisher 2 was just 30 minutes behind schedule.
But the team are also focusing on 57-year-old Frenchman Olivier de Kersauson, who set off to break the record two weeks earlier in his giant trimaran Geronimo.
De Kersauson is about 50 hours ahead of Kingfisher 2 but MacArthur's team have enjoyed fast Southern Ocean conditions and posted five straight 500-mile days to close the gap.