Welcome to Race Day 9 of the 35th America’s Cup, presented by Louis Vuitton.

This is the second day of the Louis Vuitton Challenger Play-off Semi-finals. Two races will be held today in each of two brackets in this best-of-nine knockout round.

We have wind in the Great Sound. Lots of wind.

Weather

Forecasters expect an 18-knot southerly breeze that should veer south-southwesterly and build to up to 22 knots, gusting to 30 during the race window.

Early morning the wind at Morgan’s Point, the south end of the Great Sound, was gusting to 17.7 knots out of the south-southwest.

Races today should feature longer legs and more of them to maintain the time span of 20 to 22 minutes per match. The wind direction will provide for optimum racing with an interesting breeze off the hills, flat water at the top end in the south and a chop at the bottom marks out towards Spanish Point.

The races will alternate between Artemis Racing v Softbank Team Japan matches and Emirates Team New Zealand v Land Rover BAR. The teams will also alternate their side of entry, with Softbank Team Japan and Land Rover BAR choosing a port-tack entry for their first starts of the day.

“We’ve seen the boats doing 46 knots in 18-20 knots of wind,” race director Iain Murray said yesterday. “These boats are not trying to go 50 knots; they are trying to get to the bottom mark as fast as they can.”

In other words, the boats are focused on VMG (velocity made good) to the bottom mark, not just speed.

The fastest speed is through the turn with the true wind going from 100 degrees to 140 degrees through the “power zone” or if the wind is up the “death zone”, as the teams call it.

The mandatory rules are that the average wind cannot exceed 24 knots during the sampling period that ends three minutes before the start.

The only reason to cancel a race after that comes down to Murray’s judgment as to whether “we are in a dangerous situation. If a boat capsizes we will ‘black flag’ the race and award the race to the non-capsized boat”.

Murray also clarified that in the America’s Cup Match, Oracle have to win seven races to keep the Cup. Their opponents start with minus-one and therefore must win eight races to take the Cup from the defender.

Schedule

SF1, Race 3: SoftBank Team Japan v Artemis Racing (2.08pm)

SF1, Race 3: Land Rover BAR v Emirates Team New Zealand (2.36pm)

SF1, Race 4: Artemis Racing v SoftBank Team Japan (3pm)

SF1 Race 4: Emirates Team New Zealand v Land Rover BAR (3.30pm)

Monday review

“It’s a technical sport and you have to take it on the chin and deal with it.”

What an unfortunate start for Sir Ben Ainslie and Land Rover BAR when not four minutes into their first race against Emirates Team New Zealand in the Louis Vuitton America’s Cup Challenger Play-offs, the British heard an ominous bang from within the wing, leading to Ainslie alerting America’s Cup Race Management that they must retire. Needing to carefully limp back to base to prevent further damage, there was not enough time before their next race even for a pitstop to swap out to the other wing, and BAR called it a day.

With full confidence in his shore crew, Ainslie promised they would be back on the course on Tuesday stronger than ever, and plans to even add some upgrades to raise the bar against the Kiwis.

Artemis Racing and SoftBank Team Japan split the day, each team capitalising, and being punished, in the shifty 13 to 14-knot conditions. Artemis gained the early advantage in race one, but SoftBank Team Japan rallied back in leg three, sailing to the edge of the boundary to nail the shift, laddering their way up the course to overtake the Swedes and take the victory.

In race two, Dean Barker and Team Japan won the pre-start and led around the first third of the race. But one misstep, literally, by Barker in a sloppy gybe opened the door for the Swedes to begin closing the gap. The boundary on leg four forced them into near-simultaneous gybes, which Artemis executed cleanly to accelerate, ultimately claiming the point to even the teams on the day.

•For the course guide and other related information, click on the PDF link under “Related Media”