Why do some Route legs suddenly disappear when zoomed out?
This is erroneous route-leg reversing, this has to do with the Earth being round (well..spherical), so two directions are possible between any two points. A convenient feature with the C-MAP charts is that it can be wrapped from the left or right edges, however route legs crossing the 180 longitude may be drawn to go around the Earth the other way, ie: without crossing the dateline. SOB takes its best guess at which way the route leg should logically go, anyway, the route should “repair” itself whenever the chart “pan” or “zoom” is such that ambiguity is removed!
