And handy link to technique and loads in apparent wind sailing/foiling.

https://www.northsails.com/sailing/en/resources/north-sails-international-moth-speed-guide

Pertinent here I think because of the discussion around US boat easing the main and runners.

Part of the different bit has to be that the lateral resistance, drag and main lift is significantly offset from the centreline, with a rudder and controlling foil still on the centre line.

I thought about that, and then I wondered how much of the total drag is water on foils and how much is air on hull and rig.

I think we’re overthinking it…once that rudder wing was ventilating, the stern is going down, the bow is going up, the angle of attack of the front wing massively increases, giving even more lift, and it shoots out of the water. Once out of the water..no lift. splat.

As to why the rear wing was ventilating..you’d need several degrees in hydrodynamics to figure that out I suspect!

once that rudder wing was ventilating, the stern is going down

I didn’t know it was the rudder wing ventilating, I thought it was the blade – but maybe it’s the wing that steers the boat? I can see why the wing ventilating means losing control of trim, but not why that necessarily drops the stern. I’m tending to think that the heel lifted the hull and then the apparent wind under it lifted the nose, like Donald Campbell’s Bluebird. While Bluebird was going six times as fast, Patriot is 3 times as long (and so probably 9 times the plan area) and only 3 times as heavy.

From Andrew Campbell, the flight controller on American Magic:

According to Campbell, they tried everything to minimise the impact – but were left helpless once the boat headed skyward.

“When we did get round the top …we didn’t quite manage to get the rudder through that turn. On the [TV] replays you can see the rudder sink [and] at that point you don’t really have any more control over the foils at all.

“No amount of minimum flap is going to bring the hull back down at that point [and] you’re just waiting to see if you can get any grip on that foil at all to cushion the boat on the way down.”

RR2 RR3 starting at 3am ish tomorrow morning for us

/pedant!!

Who is getting up early/not going to bed to watch Ineos vs Luna Rosa.

No!
Actually I’m doing my vaccination training all day tomorrow so won’t get to see it until tomorrow night at the earliest.
Very much hoping that they get the first strike in to put them into the finals.

I’ll record it and watch it when I get up. What’s the forecast conditions?

Read the report – sounds like an amazing race.
Well done ineos…. Who’d a thunk it 4 weeks ago!

Plenty of work still to do.

I want to see them racing in 12 knots again to see if they have actually sacrificed strong wind performance for more mid range.

What do the racers on here think about that last leg protest?

Thanks – from a non racer it certainly seemed like LR turned off their racing line to force a penalty as they had otherwise lost.

Great race.

Yep Cunningham flattens the upper part of the main and opens the upper leach.

(Flatter sail is “depowered” but also potentially ultimately faster”

Did they fix the cunningham before the race or just put it on and tie it off so they where less than optimum downwind?

Whats going on with this possible DSQ hanging over them with a problem with the measurement of their outhaul? Shouldn’t all this crap be sorted before this stage?

So not any real chance of being DSQ unless some other measurement/rule is broken?

It’s not like previous cups where there have been events on set dates where you have to show the opposition the underside of your boat so unless one of the other teams is holding an ace card of knowing about a violation but hasn’t reported it, and the measurers haven’t noticed it then it’s a nonissue.

Thanks – from a non racer it certainly seemed like LR turned off their racing line to force a penalty as they had otherwise lost.

It’s not like motor racing where you get to make one correction per corner then have to hold your line. You can’t make a sudden change of course and cause a collision, but LR’s tactic was pretty obvious so I’m not sure what nuance it’s judged on. To me I think Ineos had all the time in the world to see what was going to happen. Although I suspect LR was losing boatspeed so if Ineos had gybed they would still have won because LR was going to have to luff up again to pick up speed to gybe back for the line.

I don’t sail a downwind VMG boat so I’m not sure how the rules work with regard to propper course and downwind ley lines. But if I was on a starboard gype and an opponent was on port I’d be bullying them off the course because unlike upwind they cant tack off and become the leeward boat and luff you, you get to luff them.

I don’t sail a downwind VMG boat so I’m not sure how the rules work with regard to propper course and downwind ley lines. But if I was on a starboard gype and an opponent was on port I’d be bullying them off the course because unlike upwind they cant tack off and become the leeward boat and luff you, you get to luff them.

These high speed boats are insane in the way they go round the course sheeted in all the time but although they look like magic is going on I’m sure they are limited by laylines. 🙂
Watching this racing has been great and I’ve been up early to watch it live for the last couple of hours of the shows. I used to think windsurfing was fast.

Video about the repairs to Patriot. It’s a huge new panel that’s been made!

So it’s a first to 4 wins Semi, then a first to 7 final.

Rita seems to be the only boat with a flat bottom. The others all have a pointed bottom to the keel. Is there a technical reason for the difference?