Tuesday, June 23, 2015

The RS Aero 9 is Too Fast

For those new to the story, the RS Aero has 3 rigs, with sails of approximately 5, 7 and 9 square meters.

RS Sailing recommend them for people of different body weights.

Many RS Aero owners are buying the boat with more than one rig. Some sailors may use a 7 or 9 rig most of the time but also have a rig one step down for heavier wind conditions. Or, like me, they may have a 7 rig for most conditions but also have a 9 rig for those lighter wind days.

Of course, other things being equal, the boat with a larger rig should be faster. But is a 9 rig with a heavy sailor much faster than a 7 rig with a lighter sailor? In heavier winds can a sailor in a 5 rig beat a sailor in a 7 rig who is overpowered?

We have been trying to work out how we are going to race the Aeros at our lake. What we have discovered so far is…

1. Lasers and Aeros seem to be quite comparable in speed and we are having close competitive racing by starting Lasers and Aeros together.

2. The 5 rig is indeed an excellent option for a sailor who finds the 7 rig too much to handle on a very windy day.

3. The first day we raced 9 and 7 rigs together the three boats finished a 30 minute race within a second of each other.

The Seattle RS Aero fleet have also been trying to work out how to race the different Aero rigs together. Here is what Seattle Aero sailor Michael O'Brien wrote in a comment to my post Three Flavors of RS Aero.

When we have a regatta with 10-20 boats per rig size ... no problem. Race in per-rig fleets. 
But for now, while building fleets, I favor scratch racing where you can use any rig in any race. It is simpler and works surprisingly well. As you say, the 7 and 9 have differences in speed, but when sailor weight is factored in -- it is often the sailor weight that is the bigger factor. Rig size gives the heavier and lighter sailor the chance to extend their range both up and down.
Our experience seemed to support the same conclusion.

But it seem we may have been wrong.

On Sunday the winds were very light. Maybe 5 knots at best but often much less than that and sometimes only 0-1. The water was flat (of course). There was a light drizzle at times.

In these conditions the RS Aero 9 blew the Lasers and the RS Aero 7 away.

I am the heaviest Aero sailor in our fleet. I was sailing the Aero 9.

Upwind it was easy for me to establish a lead on the rest of the fleet. Although, in the first race one Laser sailor did stay within a few boat lengths of me on the first beat.

Downwind I don't think the Aero 9 had much of an advantage, if any.  I was passed on one run by a Laser and the Aero 7 also closed the gap on me. I suspect I don't really know how to sail the Aero properly downwind in light airs yet. Or maybe I am just too fat.

I won both races by a considerable margin. And it was all due to distance gained upwind.

After the two official races, we asked the race committee to give us a start for a "race" back to the club. It was a reach all the way. The Aero 9 pulled out in front of the Lasers and Aero 7 immediately after the start, and just kept extending its lead.

In these conditions, it seems the RS Aero 9 is way too fast for fair scratch racing with Lasers and smaller Aero rigs.

But it did feel good!

I love my RS Aero 9!

Further research is indicated.


Buff Staysail said...

More power!! We need to dial this rig all the way up to 11!!

Tillerman said...

LOL Buff. I agree. As we drifted out to the course on Sunday, the first thing one of the RC said to me was, "Do they make an 11 rig for that thing yet?"

Seriously, even if we eventually decide that 7 and 9 rigs can't race fairly together (without a handicap system) I will still keep my 9 rig for recreational sailing on days like Sunday. It reminds me of when I sailed the Rooster 8.1 rig (bigger rig for the Laser) in Minorca. It's such a pleasure to sail a boat that still feels powered up in the very light stuff.

Actually downwind I was fantasizing about how I really wanted an asymmetric spinnaker as well as the bigger sail. Maybe I should really have bought an RS100?

Michael O'Brien said...

We've experienced similar results: the 9 is quite a bit faster upwind than the 7 in light air, especially in very light air. As the breeze gets up to 9-10 kts, the gap rapidly diminishes.

We've found in the gap between Lasers and Aeros is bigger in light air than in heavier air. We've been starting 3 minutes behind and have been catching the tail of the laser fleet by the first mark and passing many downwind. In one race, we passed the leading Lasers by the finish in a 20 minute race (and these are very good laser sailors). Initially, there seemed to be less advantage downwind, but as our technique is improving, that advantage over Lasers is increasing -- to be expected. In heavier air, we were much more even both upwind and down.

Tillerman said...

Very interesting Michael.

When you say that you have a big advantage over Lasers in light air, are you talking about 9 rigs vs Lasers, or 7 rigs vs Lasers, or both?

Michael O'Brien said...

Both if the air is very light. But the 7 is also faster than the Laser in light air. It is just the 9 is quite superior under 8 knots.

Regarding the comment about Laser and Aero being more even in heavy air -- that is where our Aero experience is least. So it could be that there is a lot of untapped speed for us in the Aero in heavy air. Last week Dan Falk (a very good laser sailor) came out to test the Aero in 20+. He absolutely schooled us. Hiking hard and with good technique, the played with the boat like a toy. He was aggressive downwind and FAST. Upwind, he just powered away. There is a lot of untapped potential here.

SoxSail said...

The solution is a) everyone sails 9-rigs in light air and b) Lasers need super rigs (the 8.1's I guess?) for heavy air.

Tillerman said...

Michael - we have raced Lasers agains Aeros in 20+ and found 7s and Lasers quite similar. Having said that, I am sure we are not sailing the Aeros up to their potential yet.

SoxSail - I like that idea. One of our fleet doesn't own a 9 rig (yet) but as he is the lightest member of the fleet he will probably destroy us all if he does buy a 9 rig.

And I am all in favor of Rooster 8.1 rigs for the Lasers in light air. Nobody at the club has one as far as I know. Maybe I should get one to set an example?

Michael O'Brien said...

We've got one Rooster 8.1 rig locally. It is nowhere near as good a sail/rig combination as the Aero 9. It is more like a franken-laser.

Sandy Goodall said...

Try the "Fat Head" Laser sail from Intensity Sails?

Jay Eveleth said...

You are convincing me that I am on the right track with the Kittihawk14. It doesn't care how fast the wind blows because when hiking no longer holds the boat down, you merely deploy the anti-heeling hydrofoils. Then if the wind speed increases, so does the boat speed and so does the righting force. Using this approach, I would go for an Aero 15, or an Aero with a gennaker and/or jib.

Tillerman said...

Jay - there was quite a bit of debate in the Laser class about larger rigs and in particular whether they placed too much stress on the mast step. One point of view was that the heeling force in the sail was always balanced by the weight of the sailor fully hiked, and as the latter didn't change you couldn't possibly be putting more stress on the mast step with a bigger sail.

But that doesn't apply with anti-heeling hydrofoils. Now the heeling force is balanced by the weight of the sailor AND the anti-heeling force from the foils. I hope the Kittihawk 14 has a good sturdy mast step!

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