Polar Diagrams

Here is some info on what polar diagrams is and how to create/use them:

The speed polar diagram is the graphical diagram, consisting of the theoretical maximum boat speeds at various true wind speeds and headings, along with the associated upwind and downwind VMGs (velocities made good).

Polar Diagrams are used to determine the optimum course to sail, given existing wind conditions.

Where can you get a polar diagram for a sailboat?
Typically from the boat manufacturer if they had one made. Most cruising class boats especially those built by small manufacturers will likely not exist.

Math behind the sailboat polar diagrams:
http://icwww.epfl.ch/~sam/IntCP05/Herrero-etal.pdf

Excel Polar Diagrams Turorials:

Here's a intro tutorial on the Radar chart in General:
http://office.microsoft.com/en-us/excel/HA102186721033.aspx

Excel 2007
http://office.microsoft.com/en-us/excel/results.aspx?qu=Drawing&sc=9&av=...

Excel 2003
http://office.microsoft.com/en-us/excel/HP052364981033.aspx

There is a very useful article on how to create Polar Diagram in Excel by Dr. Eugene F.M. O'Loughlin:
http://eoloughlin.blogspot.com/2008/12/how-todraw-polar-diagram-in-excel.html

And the video: