I found in the very first sector about 8 zones (1 to

The second sector has one highway but when flying along the highway I find 3 zones numbered 1, 2, 4. So there has to be at least a third zone.
Any clues where and how many other zones there are?
In the second sector I really have no clue at all. In the first I am just following the navigation buoys or following ships to sectors which have no "officialy" marked way (for reasons).
This is kinda impossible in the second sector as the sector is wide open and I don't have a place to "start".
Thanks