Monday, March 13, 2017

Comparing Laser and Aero Foils

Aero Rudder
The first thing you notice when going from a Laser to an Aero is how responsive the boat is to the rudder and how light the rudder feels.

Upwind there is hardly any pressure on the tiller. Holding the tiller on a Laser upwind in a breeze puts real tension in the steering arm, there is significant weather helm, a big contributor to fore arm muscle strain.

Both boats need a lot of sheeting and this is hard on the sheeting arm. The Aero having a light helm gives one arm a break on each tack.

The Aero foils certainly look more efficient, the modern materials help and it is interesting to compare them.

The Laser rudder has a defined rake which is the cause the strong weather helm feel upwind. The Aero rudder is almost vertical.





Laser rudder



Both rudders probably have the same braking effect. When the two rudders are placed over each other they appear to have a similar surface area. The Aero rudder is longer and deeper in the water and has minimal rake which accounts for light weather helm feel.

The Aero rudder is very effective at steering while the Laser rudder lacks bite off the wind and down wind.

Downwind the Aero rudder actually works and the boat can be steered under rig adding to stability in 20+ knot runs.  The Aeros flat wide hull at the back also adds considerable stability.







Laser and Aero centre boards
Comparing the two centre boards, the Laser board seems to be a little larger, but not as deep in the water because it is raked back. The Aero centre board is deployed vertically and is skinnier and deeper.

On the water the Aero centre board is significantly better. There no vibration or humming when on plane, the board is properly fitted in its slot and does not ride up like the Laser board.


Aero rudder over Laser rudder
There is a trap to the Aero's more effective rudder and its light feel. Dinghy's are slowed by using the rudder, it acts as a brake.

Greater care has to be taken when using the rudder on the Aero,  it works so well to turn the boat it is tempting to over use it.  It is worth remembering Steve Cockerill's advice about using weight and sheeting to help steer.

Upwind on the in light/moderate breeze I hold the tiller extension as lightly as possible. This gives feedback to keep the boat flat just near the point where it is past flat and the balance changes to a lee helm.

The light hull weight means you have to scoot in and out a lot in puffy conditions. Fortunately the shape of the deck facilitates this, but more on this feature in future posts.


















2 comments:

  1. Great Blog Nick, well done on 2nd at the Nat's as well, you sailed the conditions brilliantly. One thing you didn't mention about the foils was the trailing edge, the designers have made this a mitre. When I first test sailed one I thought this had been filed to remove some dings, but on receiving my own boat the mitred edges were still present. I am pretty sure RS have not made mention of this in previous literature but my thoughts are by creating a laminar flow away from the rudder, cavitation is avoided and the boat steers even more effectively downwind than the Laser. I would be interested in your or anyone else's thoughts on this.

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  2. Hi Andrew, great to hear from you, challenging regatta at Black Rock, crazier waves than I am used to, even though I often practice near the entrance to Sydney Harbour in quite big seas.

    I will message Peter Barton to see what RS have to say about this, could make an interesting blog post. Thanks for following RS Aero Sydney FB. If you are ever in Sydney let us know and we will organise a loan of an Aero, experience one of the best harbours on the planet to sail an Aero.

    Cheers Nick

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