So guys, I've just finished my first garmin watch app targeting sailing, kiting, windsurfing, and it's free.
In the connect IQ store.
App Name : sail Racer
Included speed, max speed, VMG directly upwind, angle off the wind, track , elapsed distance, session recording with Google earth output, speed graph .... and the masterpiece
In the main menu a polar logger. It records max speed against all compass headings, and saves so you can make a polar graph using excell to find out your target speeds to give best upwind or downwind performance. Let me know what you think, or if you have any suggestions I can implement