The chart draws your boat, the traffic around it, and, while you steer to a mark, the laylines to that mark. All three come from the boat's instruments when they are connected.
Own ship
The boat symbol points along your heading. Two lines run ahead of it:
- The heading line, straight off the bow.
- The course-over-ground vector, where you will be in a few minutes at your present speed and course over ground, with ticks along it.
Set how many minutes the lines reach in Settings › Cockpit › Course and heading lines.
The position comes from the boat's instruments when they are reporting, or else from the phone's GPS. Between fixes the symbol moves smoothly along your course rather than jumping once a second. The boat is always drawn above the chart's symbols and labels.
AIS targets
When the boat's AIS reaches the app through its instrument connection, each target is drawn on the chart, labeled with its name or MMSI, with a vector along its course where it is moving.
- A dangerous target is drawn in the warning style, and its label adds the closest point of approach and when, for example CPA 0.24 nm in 6 min. It stays on the chart at every declutter level.
- A stale target, one not heard from for a while, is drawn faded and loses its vector.
Boats from your race's tracker, when the project has one attached, are drawn separately with their sail number, name and trail.
Laylines
While you navigate to a mark and the instruments give a true wind direction, the chart draws the laylines to that mark. Upwind they use your target wind angle, or 45° when there is none. Downwind they use your target downwind angle, or 150°.
A band either side of each layline shows how far a wind shift would move it. Set its width in Settings › Cockpit › Layline wind-shift band, from 0 to ±20°.
Limits
Without instruments, the chart has only the phone's GPS. It then has no heading line, no AIS and no laylines. AIS targets cannot be tapped for a card.