Speed Fence
For sailboat racing, the concept of a speed fence was developed by SailBlogs to enhance the standard Google Earth feed.
First used in support of Pete Goss' Round Britian and Ireland 2006 participation, the concept was to visually illustrate the speed of the boat on the map without needing to display the boat's speed in knots or force the user to open the point balloon.
To create the fence, the speed of the boat is multiplied by 1000, and a polygon created to this height. This concept has been very well received and imitated by other sites.
Colors
There are 7 color ranges to a speed fence, configurable in the Map Properties. A value of 4, for example, will set up the 7 ranges to have values of:
- 0-3 Kts.
- 4-7 Kts.
- 8-11 Kts.
- 12-15 Kts.
- 16-19 Kts.
- 20-23 Kts.
- 24-27 Kts.
References
Pete Goss in 2006 Shetland Round Britain and Ireland Race - Google Earth Blog, June 18, 2006