Distances
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Hi,
I currently use Windy Premium and trying "distance and planification" function I have found many distance distorsion beween Navionics boating from Garmin and Windy, despite I have imported navionics route (with manual update and not automated) into Windy. And I have checked it is the same route on both sides.
It is a route composed of 20 waypoints along atlantic coast in France, the total length of the route is 238 Miles for Navionics and 274 Miles for Windy.
Is it a bug, what could be the explanation? -
@Phigros Hello, can you please provide screenshots that can be compared?
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@Phigros
I don’t know if it is the reason for this distance inaccuracy, but Windy and Navionics don’t plot routes in the same way.
Windy plots routes along great circles (orthodromic courses) i.e. the shorter route.
While Navionics uses rhumb line routes (loxodromic courses) i.e. at constant heading.
But if you make a test from the Raz de Sein at the head of Britanny to Llanes on the Spanish coast you will probably get a very small discrepancy. Because along a meridian, great circle routes and rhumb line routes are identical.
