Cup Spy May 9: Luna Rossa coach gives early verdict on the latest AC75
by Richard Gladwell/Sail-World NZ 10 May 14:52 UTC
9 May 2024
Luna Rossa - AC75 - Day 12 - May 9, 2024 - Cagliari © Ivo Rovira / America's Cup
Luna Rossa, the Challenger for the 2021 America's Cup sailed for the fourth successive day from Cagliari, Sardinia. While the Kiwis resumed their AC40 race training on a beautiful, but cold day on the Waitemata Harbour.
What happened in the Cup - May 9, 2024:
- Luna Rossa Prada Pirelli: Sailed their AC75 raceboat for the fourth successive day, off the base in Sardinia.
- Emirates Team New Zealand: Stopped sailing on May 1. Is now backing their AC75 for Barcelona - expected to resume sailing in early July. They resumed what coach Ray Davies says will be an intensive sailing block pitching their AC75 crew against a training crew. The Youth and Womens America's Cup teams will also be training in the AC40s in this block.
- Alinghi Red Bull Racing: Did not sail, but has sailed five days out of nine in May.
- American Magic: Launched their AC75 on May 7, and had a day off the water, after yesterday's pleasing session.
- Orient Express Racing Team: No AC37 Recon Team report. A launch date has yet to be publicly advised for their AC75 raceboat.
- INEOS Britannia: Stayed off the water - having sailed on Tuesday and Wednesday of this week.
Commentary: A Tale of two Foils:
A point of interest on Thursday was the relative performance of Luna Rossa's two wing foils - one to the new AC75 Class Rule - being lighter, wider and deeper, and the other a legacy foil from the 2021 America's cup.
The weather was ideal for comparison - light winds and flat water.
Luna Rossa coach, Phillipe Presti said after the session that it was a little early to judge the full capabilities of the new Class Rule and the foils it produces.
"We see how it works with two boards. But there doesn't seem any problem to go high mode, low mode, fast acceleration and this is an improvement overall for the boat. I don't see any downside."
"The boats are nothing like what we had last time," he said comparing the latest AC75 to those used in the 2021 America's Cup in Auckland. "This is new generation of boats and they are way quicker and agile. At the low end [of the wind range] we can take took off at 6.5kts or 6.9kts (true wind speed). So they are really a machine - a wind machine."
The quick overview of the new rules that govern the foil arm and wingfoils between the 2021 and 2024 AC75s are that the foil arm is still a supplied one design part, unchanged from that used in the 2021 Cup. The combined weight of the wingfoil and its foil arm has been reduced by 115kg (giving a 230kg total reduction in weight from both foils).
The depth of the wingfoil has increased by 250mm from the 2021 Class Rule. Also the span of each 2024 wingfoil has increased by 250mm over the 2021 version. With other changes to the AC75 Class Rule the boat weight has dropped from a minimum weight of 7570kg to 6786kg or a reduction of 784kg. Sailing with one set of 2021 foils and the other being 2024 class rule compliant, it follows that coach Presti is basing his comments regarding lift-off on a boat that can be 115kg lighter than Luna Rossa is at present.
Maneuverability may be improved by the wider span of wingfoil having a better grip.
The reason for the spike appendage is not known. It could be as a method of getting extra weight into the foil, without adding it to the wings and bulb - the effect of which would be to carry extra weight to meet the minimum required by the Class Rule, without adding to underwater drag.
It would also appear to facilitate getting the wing foil further forward in the boat.
The new wing foil also appears pierce the water surface with less fuss, than the legacy foil. However as it is flat, its wing tip usually pierces the surface as well as the foil arm.
The AC37 Joint Recon team provided plenty of images showing some subtle and not so subtle differences between the two foils. A new wingfoil is expected to be fitted to the port foil arm in the next few days.
AC37 Joint Recon Team Reports:
Luna Rossa - AC75 - Day 12 - May 9, 2024 - Cagliari
Luna Rossa Prada Pirelli team rolled out their new AC75 'B3' at 11:30hrs and docked out two hours later at 13:30hrs.
Main M1-7 was hoisted with the largest jib J1-7 as the breeze was measured 4-6ts from 200 degrees with flat seastate.
Due to this light air, B3 was towed foilborne on port tack while it was able to sail consistently with larger induced windward heel. After tacking to starboard tack, it bore away and fell hullborne exiting the gybe, another tow up followed. On the following shorter stint, it was noted that the yacht struggled slightly more executing dry tacks when transiting from starboard to port tack, hence exiting on the new wing in this lightest air.
At 14:35hrs the breeze had picked up slightly with 5-7kts from 195 degrees and another balanced and clean self take off was observed on port tack 90 degrees TWA and 15-16kn boat speed.
This led into the first consistent foiling session of the day with a solid number of light air maneuvers in addition to some moding.
At 15:10hrs, the breeze was measured 7-9kts and the J1-7 was lowered to hoist the J1.5-4. Once up and foiling on port tack, the yacht completed the usual training routine beginning with a series of tacks, bearing away on port tack for a series of gybes and trimming up again on port tack.
During the longer straightline sailing legs the team seemed to be running different upwind and downwind modes. Gybes from starboard to port tack often resulted in touch and go exits and the starboard arm raise was much slower compared to its opposite's transition in the lightest air.
Physical marks were placed for a leeward gate and virtual marks were used for the windward one.
As the yacht hove to, crew rotations were arranged for: starboard helm, starboard trimmer and both aft pods cyclors. In addition three batteries were seen being changed for the hydro systems. By then, B3 was foilborne for approx. 75 minute in total, fairly distributed between the two last longer runs, and 40 maneuvers were executed.
After a short break with technicians on board, the yacht self took off on port tack and two starts were practiced before sailing two legs and sailing slowly on the downwind leg with sailors checking the new jib sheeting system.
The breeze had increased further to 8-10kn and the yacht practiced three additional starts spending about two minutes in the box following standard procedure: trimming up to the right and coming down on the line. Four legs were sailed after the last drill before B3 extended the downwind leg executing a solid number of consistent gybes towards the harbour in 7-9kts.
The day was called with approximately 135 minutes foilborne, 42 tacks and 37 gybes
[From: Michele Melis AC Recon AC37 Joint Recon Team]
Crew - Sailing:Marco Gradoni (port), Jimmy Spithill (stb) (Checco Bruni swapped with Marco Gradoni), Andrea Tesei(stb), Umberto Molineris (port) (swapped with Vittorio Bissaro)
Crew - Power: Bruno Rosetti(stb fwd) Enrico Voltolini(port fwd), Cesare Gabbia(port aft), Luca Kirwan (stb aft) (these last two swapped with Paolo Simion and Mattia Camboni)
Session Statistics: Luna Rossa - AC75 - Day 12 - May 9, 2024 - Cagliari
- Weather: 20 degrees Cloudy
- Wind Strength: 4-10kts
- Wind Direction: 180 degrees - 200 degrees
- Sea State: 0.3mtr
- Crane In: 1150hrs Dock Out: 1330hrs
- Dock In: 1740hrs Crane out:
- Takeoff Angle TWA: 080-090 degrees Speed: 14-16kts
- Total Tacks: 42 Fully Foiling: 31 Touch & Go: 8 Touch Down: 3
- Total Gybes: 37 Fully Foiling: 29 Touch & Go: 6 Touch Down: 2
Emirates Team New Zealand - AC40 - Day 75 - May 9, 2024 - Auckland
After some time off for other sailing commitments, ETNZ got back on the water today, heading out for some two-boat testing with LEQ12 and AC40 OD.
Heading off the dock just before midday into a crisp winter's day, LEQ 12 met the AC40 OD in the 'Back Paddock' (Course E) and got straight into some tune-up sailing around the short course that had been laid. A crew swap from the youth and women's team to the AC40 'B Team' which consisted of Josh Junior, Sam Meech, Marcus Hansen, and Gemma Jones.
The teams spent a short time doing some boat-on-boat sailing up and down the track and got into pre-start practice. With both boats well-powered and in range on their match sail choices, it made for some good aggressive pre-start practice. AC40 OD did a good job of pushing and controlling LEQ12's lead back to the line, and despite the speed advantage of LEQ12, won a couple of starts this way.
During all these starts, the boats worked very hard on completing dynamic boat handling maneuvers and would pay the price when getting it wrong. LEQ12 seen falling off the foil exiting a tack after being luffed by AC40 OD, a maneuver which secured the start win.
In this wind range, the LEQ12 did have a strength in line speed advantage; however, it wasn't enough to sail away, and AC40 would be able to pick the right shift and stay in the race around the track.
After three rounds of three starts then racing the last full race, the team made headway for the dock and called it a day.
Recon had an interview with Ray Davies and discussed the upcoming sailing block and the test block that they have just wrapped up.
Sailing Crew: Peter Burling, Blair Tuke, Andy Maloney, Nathan Outteridge
Session Statistics: Emirates Team New Zealand - AC40 - Day 75 - May 9, 2024 - Auckland
- Weather: 9-15 degrees
- Wind Strength 10-15kts
- Wind Direction: 165 degrees - 175 degrees
- Sea State: 0.1mtrs
- Crane In: 1100hrs Dock Out: 1200hrs
- Dock In: 1600hrs Crane out: 1630hrs
- Takeoff Angle TWA: degrees Speed: kts
- Total Tacks: NA - Fully foiling: NA; Touch & Go: 0; Touch Down: 0
- Total Gybes: NA - Fully foiling: NA; Touch & Go: 0; Touch Down: 0
Additional Images:
This commentary was written and compiled from video, still images and statistical content extracted from the AC37 Joint Recon program and other material available to Sail-World NZ, including photo files and other on the water coverage from the 2010, 2013, and 2017 and 2021 America's Cups. Its format is intended to give Sail-World readers a snapshot of all teams' progress on a given day or period.