The map is not to scale. The ocean is much wider than shown.
Since the end of the Second Age, the Undying Lands (at the far left of the map) are no longer in the same plane of existence as the mortal world.
"Alqualonde is straight west of the Gulf of Luin far enough to be in open sea but close enough to explain Elwing's fast flight. That puts it at a latitude similar to northern Europe and in the northern latitude for the snow and icebergs.
So Alqualonde is far west of middle earth. Sylvhara is southwest in uncharted waters, in warmer waters."
