Author Topic: Upwind Target Boatspeed  (Read 204 times)

prochase

  • U20 Virgin
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Upwind Target Boatspeed
« on: May 22, 2018, 08:07:42 PM »
Just purchased a U20 and a new Speedpuck and will be racing PHRF. Can anyone provide target upwind boat speed numbers based upon windspeed? I contacted Don Corey and he says there was never a polar diagram created for the boat.

We participated in our first race last weekend and the Speedpuck was all over the place, one sec it would read 4.8 and the next sec 5.4 without any change in windspeed or sail or boat trim. The Speedpuck does have a damping feature to level out GPS data rate. Would be interested if anyone has adjusted the factory default of 1 sec speed reporting.
 
Used to sailing a Melges 24 by the numbers for speed taken from the polars and sailmaker recommendations for shroud tension.

Thank you,


Eric
Hull #159

Lighten Up 31

  • U20 Virgin
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Re: Upwind Target Boatspeed
« Reply #1 on: May 28, 2018, 06:49:58 PM »
IMHO the U20 is better sailed by feel than with instruments. The Speedpuck and is better for telling you how fast you went, rather than how fast you are going. Years ago I made the mistake of purchasing the Tactick compass with both speed and depth sensors. Drilled nice holes through the bottom of the hull that I now regret having to patch. I sail faster with it off the boat and me instead looking at the sails and feeling the boat accelerate and move.

Upwind notes: As I understand it, the high aspect ratio keep allows the boat to out point most other boats like a J24 or even a J80. While this is useful in a tactical sense, the boat will not have a high VMG that way. The strategy I have heard over and over through the years is to keep the boat moving. I pinch up until I feel the boat start to slow, then I back off. Better to use the traveler and then the sheet rather than pinching up when the boat becomes overpowered. In light winds keep the boat healed.

Downwind: Keep the boat on plane if possible. Just like on the Melges.

Now given that I will probably upgrade to a speedpuck soon. Not for racing but for fun, because everyone wants to know how fast they are going.
David Kennedy
#31 Lighten Up
McCall Idaho

Mark Allen

  • #26 JUNTA
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Re: Upwind Target Boatspeed
« Reply #2 on: May 28, 2018, 09:51:07 PM »
The boat does not have a set of polars from the designer. Jim artrim could work some up for you if you wish to pay for them. I have asked in the past. I agree with David, the boat is more of a feel from your ass to know if you are sailing fast or slow. The class is more of sailor on sailor then instrument on instrument.

Mark
#26 JUNTA
Duck or Die!

prochase

  • U20 Virgin
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  • Posts: 2
Re: Upwind Target Boatspeed
« Reply #3 on: May 29, 2018, 01:55:26 PM »
Thanks for the input guys and I appreciate you taking time to respond. Yes, you can't pinch these sportboats, learned that the hard way on the Melges.

Will try what you say and see how things go.

Best Regards,

Eric