ocean colour around ships

[godfather]

When click on a ship/sub hexes around the ship turn lite blue, but not as many as would be when showing my movement range. is this my sight range? What do the grey hexes signify?

[pk867]

Hi,

I will take a stab at this. The light blue hexes signify your current spotting range due to weather. The grey hexes shows that they are under FoW (Fog of War)
and that there could be enemy ships in those areas. They will become visible if you move to use your spotting range to look into those grey areas. Subs
will be hidden unless they attack a surface naval unit.