The composite wind instrument combines apparent and true wind angles and speeds with vessel heading and course over ground. Its annular face leaves the center mostly transparent so chart content remains visible.

The instrument accepts six independently selectable Signal K paths:

Signal K angles are converted from radians to degrees. Speeds are converted from metres per second to knots. Missing or timed-out values are replaced by dashes without hiding the remaining current data.

The heading input is treated as magnetic and corrected with OpenCPN’s current magnetic variation before it is drawn against the true-north chart.

In North up mode the compass remains fixed while heading, COG, wind markers, and the port/starboard sectors rotate. In Heading up mode the bow and colored sectors remain at the top while the compass and COG rotate relative to heading. The A and T triangles point inward because wind comes from the indicated direction; heading and COG triangles point outward.

The diameter and colors of the face, ticks, text, markers, border, and port/starboard sectors are configurable. The central opening, tick spacing, font sizes, and marker geometry are fixed.