Forums > Windsurfing   Gps and Speed talk

Maximum speeds on wave gear?

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Created by wendell > 9 months ago, 7 Aug 2022
sboardcrazy
NSW, 8224 posts
16 Apr 2023 10:17AM
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boardsurfr said..

aeroegnr said..
my angle downwind was no where near that deep. Unfortunately the flatter spot for us here was dead offshore with a large wind shadow that day.


Wind shadow is often an issue, unless you're at a super-weedy and/or very shallow spot. Sand bars tend to be less problematic than islands with greenery on top. In many "real world" spots, your best bet is to thread a path between the chop. But that limits how deep you can go, unless you have something like a point that makes changes the wave direction enough.
Here's a polar plot that shows a 10 knot speed gain when going from 90 to 130 degrees:
In the plots from better speedsailors who are faster on beam reaches, the difference can be a bit smaller. If they are really well powered, the top speed angles are often 10 or even 20 degrees deeper.



How do you read this graph? I can't get my head around it.

aeroegnr
1731 posts
16 Apr 2023 9:21AM
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sboardcrazy said..


boardsurfr said..



aeroegnr said..
my angle downwind was no where near that deep. Unfortunately the flatter spot for us here was dead offshore with a large wind shadow that day.




Wind shadow is often an issue, unless you're at a super-weedy and/or very shallow spot. Sand bars tend to be less problematic than islands with greenery on top. In many "real world" spots, your best bet is to thread a path between the chop. But that limits how deep you can go, unless you have something like a point that makes changes the wave direction enough.
Here's a polar plot that shows a 10 knot speed gain when going from 90 to 130 degrees:
In the plots from better speedsailors who are faster on beam reaches, the difference can be a bit smaller. If they are really well powered, the top speed angles are often 10 or even 20 degrees deeper.




How do you read this graph? I can't get my head around it.



Top of the graph is the wind direction. Basically wind going vertically top to bottom. Angle from top is the angle from the wind. The rings are the speed (5kts, 10kts, 15kts...out to 40kts).

So you can see that max upwind planing angle is about 60deg off of the wind, but he got very deep on the bottom right side, going 35-50+kts depending on the angle.

It really just shows angle against the wind vs. speed.

It gives up any idea of what the actual path on the water was, it just shows how the performance is vs. angle from the wind.

If you were to look at the tracks of that 40+ knot peak it would probably show him going more and more downwind until he hits max speed. These polars just show you where your max performance was over the entire session.

decrepit
WA, 12761 posts
16 Apr 2023 10:01AM
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yes, the radial dotted lines are spaced at 30degrees, so max speed was around 40deg off the wind.
The reaaly deep angle was probably in gybes.



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Forums > Windsurfing   Gps and Speed talk


"Maximum speeds on wave gear?" started by wendell