After years of practice in sailing fast foiling catamarans, just how stable are Oracle Team USA? How stable is 17, their America’s Cup Class catamaran?

Oracle, comeback winners of the America’s Cup in 2013 and now the America’s Cup defender have capsized their America’s Cup Class 50ft catamaran again. It happened this time during a Wednesday afternoon practice session on the Great Sound. They are the only team to have capsized their ACC yacht.

In a short statement issued on the team’s social media sites, Oracle commented on their second capsize in two months. They wrote: “Oracle Team USA capsized on Wednesday afternoon during a practice session focused on pre-start manoeuvres. The boat was righted within three minutes and there were no injuries to the crew or damage to the boat.”

Oracle were unlucky to capsize again, but lucky to come out unbroken. Equipment failure or extreme damage at this point would perhaps be fatal. Only two weeks remain until qualifying races start and only five weeks remain till Oracle will have to defend her title against the top challenger. Oracle and all five challengers will sail in the qualifying rounds.

Oracle will have to be careful now as three times may be the charm. Repairing a broken wing, daggerboard or rudder could take weeks. And that could be weeks lost to good practice time in the approaching summertime conditions. All teams are concerned about potential collisions with debris and turtles in the Great Sound.

Video shot by myislandhomeBDA’s Jason Smith reveals that the capsize appears to start as the team began putting crew across the boat in preparation to come up onto the wind in a pre-start manoeuvre, with the boat sailing close to top speed. After the turn started, 17 began a high-speed knock-down putting down the new leeward hull as the windward hull began to lift.

Two of the crew had stopped grinding and crossed the boat. The pre-gybe helmsman was on the new leeward side with two grinders and another driver is at the windward steering wheel. Three crew per side.

The new leeward daggerboard goes down and the windward board goes up. But 17 kept turning.

In the windward hull and probably sensing the crash coming, only one of the grinders was working, another crew member was trimming the wing and a helmsman was also at the windward wheel.

Down to leeward one grinder climbs out of his cockpit and up onto the trampoline net. He hangs on tight as the cat continues her slow death roll. The other grinder was in position. There was also a helmsman still to leeward. The top section of these wings is filled with some special type of flotation material to keep the cats from turning turtle and putting the mast top in the sandy bottom of the Sound.

Oracle’s 17 quickly went over the point of no return and settled gently on her side in the 15-18kt breeze. Practice makes perfect … the boat was righted within three minutes and there were no injuries to the crew or damage to the boat.