Which sail should I use today - why not ask your iPhone? SailSize, a free iPhone application, lets you enter your weight and the current wind, and calculates what sail size you need to get planing.
Calculations should be accurate since they are based on James Douglass' sail size spreadsheet. Available for free at the iTunes store. (And no, this is not an April Fools Day joke!)
Dahab: Freestyle, Friendliness, Cats and Sun
7 hours ago