Another yacht has been badly damaged in the America’s Cup challenger series with Japan’s Asura breaking its mast.

The Nippon Challenge boat was leading AmericaOne by about 20 seconds in racing today, when the mast snapped in half near the top as Asura moved to gybe on the approach to the fourth mark of the six-leg course. Asura’s crew were struggling to control the boat after the damaged equipment crashed onto the deck and into the water.

Further details were not immediately available.

Asura’s damage follows the cracking of Young America’s hull after it was hit by freak waves on Tuesday.

Racing conditions were reasonable on Auckland’s Hauraki Gulf, with winds averaging 17 knots and seas moderate. However the wind angles had been shifting massively during racing.