Tactical map water colors

[Wiz33]

Originally Posted by Tshark

Just curious about the different shading displayed on the tactical map. Does the shading denote ocean depth or areas of high noise?
I remember Red Storm Rising had a display that showed water sound travel conditions and used to hide in them all the time.

Thanks

From my limited experience, it seems to be water depth. I just wish it's at a higher contrast as it's hard to see between bands for these old eyes.