Ship of Bones

As for the misty fog, it began to become thicker and spreading out even more across the area

The fog slowly covers the entire area around the sea. 

It first moves slowly but then as some people began to realize the rate of which this fog is expanding is getting faster by the second

At first one could still see the figure in front of them but then as the fog grows thicker, they find it hard to even see a few feet in front of them. 

Even large ship looks like only a dark silhouette even if the distance is not that far.

The fog not only spread through the area of the ships and the surrounding of the island it also become thicker, so thick one could feel the oxygen is sucked out by this fog

Even space felt like it is being pressured by this fog. Everyone could tell that this fog is not natural, but magic made.

  Even Divine Sense is hard to operate in this kind of thick fog