Birdseye
Well-known member
Have been looking at the Avalon VPP polars for my boat and gradually getting confused. Velocity means speed but in a specified direction - its a vector and thats its definition. But what is the direction specified in a Polar. It cant be into the wind or the downwind predictions would be negative. So it has to be speed through the water.
But if it is speed through the water not velocity that the VPP is predicting, then I dont recognise the numbers and I am not being silly here - my log is adjusted to match the GPS in the flat tideless water behind the barrage gates. The differences are more than a knot.
And whilst I am asking, do polars allow for leeway?
Anyone else compared their polar from avalon with reality?
But if it is speed through the water not velocity that the VPP is predicting, then I dont recognise the numbers and I am not being silly here - my log is adjusted to match the GPS in the flat tideless water behind the barrage gates. The differences are more than a knot.
And whilst I am asking, do polars allow for leeway?
Anyone else compared their polar from avalon with reality?
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