Name: Windsurfing Stats Top5x10, Top5 Alpha500
Rating: 3.7 (3 reviews)
Author: AlexeyGimadiev

This is not an App! This is Datafield, which works with standard Garmin Apps.

Add it to your activity application and get Top5x10, top5 Alpha500  stats and more.
Speeds are in km/h or knots, screens will show up when you'll have some results.

Screen description:
0) noRec, curSpeed - right now you have no recorded 10sec runs or turns
1)  Top5x10 - avg speed for best five 10sec runs. Run ends when speed drops below 18kmh. In the top row you can see what is current (unrecorded yet) 10sec speed.
2) Top5 @500 - best 500meter runs where start and end are less then 50 meters apart. 
3) 1/9 jbs, last @500 - this screen contains count of fully planning turns (1) and total number of turns (9), and then alpha500 speed for last recorded turn.