LB, without reference to books I'd say with NVMC you remain within 3 miles of the airport until you've reached LSALT, the reverse manner in which you would make an arrival. NVMC doesn't require you to actually be able to "see" the ground or water, but to have the ability to see an object should there be sufficient light, farmhouse, road traffic, town, that is, you have to have the proscribed weather (visibility), else NVMC would be restricted to a full moon and no cloud whatsoever. IMHO