What is ground wind?

Ground wind is the speed and direction of the wind referenced to a compass rose, which is different from apparent and true wind which are referenced to the bow of the boat. The apparent and true wind are interesting to see how the wind is affecting or pushing the boat (e.g., when sailing or docking), the ground wind is important for understanding the weather (e.g., where is the low pressure). Since the WSO100 only measures apparent wind speed and direction, display products such as Maretron’s DSM150, DSM200, DSM250, and N2KView require additional information to compute and display ground wind (i.e., vessel speed, course, and heading).