Map: Height Maps

[jp10]

It is coastal on the western edge so it has zero and minus terrain level. What I believe is if I make the highest terrain 15 which in real life is 625'/200m then making a 100'/33m elevation change a 2.5 height hex then the terrain relationship of the map will relativistic to the real world location even if the game guide's consideration will not equate the level 15 hex to being 625'/200m.