4 Dimension Net Theory
The net, or Submachine, etc, is a 4 dimensional model. For those of you that don’t know, the first 3 dimensions are the aspects of space we live in, i.e. length width and depth, then there is a 4th dimension that is thought to be something like how the universe is shaped, where there is a finite(limited) amount of space and matter, but it all folds in on itself in an infinite loop. So when you come up to an edge, you go through it, but come out back at the beginning or center. The thing about 4D object is that they can be incredibly large (or at least seem to be) from the inside, but outside they can be microscopic. The idea is that if you go far enough in one direction then you will end up back at the start, such as in sub 5 where you brake down that bricked up door and end up under the lighthouse again. If the net were a 4D model that has been made or created in some way, then it would explain how you can continue for ever and never meet anyone, and seeing how people would simultaneously be in a place and not be, you would see notes from them, even if you never see them.