The anti-grounding safety pixel

Expert

The essentials

Virtual Regatta (VR) supplies the coastline as a grid of pixels. The “Anti-grounding safety pixel” setting (on by default) forbids the routing to come within one pixel of land. It matters most when the routing has to squeeze through narrow passages between islands: a point that would touch the pixel next to land is discarded, which avoids offering a route the game would consider grounded.

Narrow passage near Kodiak with the safety pixel on: the route keeps one pixel away from landNarrow passage near Kodiak with the safety pixel on: the route keeps one pixel away from land

The same passage with the safety pixel off: the route may come right up to the coastThe same passage with the safety pixel off: the route may come right up to the coast

This setting is in Settings > Routing, a section of Expert mode. Without Expert mode, it stays on.

Going further

What it really does. To know whether a point is “at sea”, the app looks at the cell of the land grid that holds the point. With the safety pixel, it also looks at the eight neighbouring cells: if one of them is land, the point is refused. This margin applies:

  • to the boat at the start of the routing: too close to land, the routing fails with “The routing failed as your boat is too close to shore. Please move your boat in VR away from shore and then come back to eSail4VR or uncheck the anti-grounding safety pixel in the eSail4VR settings.” (in Expert mode; without it, the same sentence stops before “or uncheck”);
  • to the target: “The routing target is too close to land. Please move your routing target away from land or uncheck the anti-grounding safety pixel in the eSail4VR settings.”;
  • to the legs of the calculation and the final polishing, which keep the same margin.

Unticking the setting. The routing can then hug the coast more closely: only the cell that holds the point counts. At the end of the calculation, if a point of the routing or a segment between two points is within one pixel of land, the app warns you: “You have unchecked the anti-grounding safety pixel option. A point in the routing path is within this one pixel from land. Even if you send orders as waypoints, we cannot guarantee that your boat will not run aground.” So untick it when a legitimate target sits against the coast, and then check the line by zooming in.

What it does not do.

  • It only protects from land. No margin is added around exclusion zones or the ice limit (see what the app takes into account).
  • It does not guarantee the result in the game. The message above says so: even with waypoints, the app cannot guarantee that the boat will not run aground.

The finish of the leg. When the target is the finish of the leg and it lies on land or inside the margin, the routing moves it to the nearest sea point that passes the same test, in rings of a quarter of a mile, within the finish radius or 3 miles, whichever is larger.