USGS information into useable SC4 maps ????

[cogeo]

And even if you are able to get bathymetric data, you will still need to find a way to combine them with the elevation data; the two data sets will have to coincide, and this is not easy to do, at least in any trivial way. A difference of just two or three pixels can cause you trouble, like a bumpy, choppy or abrupt coastline, which would then require manual treatment in SC4TF. So the elevation and the bathymetric data should preferably come from the same source. And as SC4TF doesn't support such features, you need to find some way to combine (merge) the two datasets yourself. Maybe convert them to 16-bit grayscale images, but this in turn requires both finding utilities to carry-out the conversions and use a 16-bit capable imaging tool; or instead, make them 8-bit and suffer the "steps" problem.

[Lowkee33]

Thanks Toga.  I went to the US mapping site, and it does indeed look like a good place to start.

The region I made is an island chain, so a fair amount of photo shop was needed to get the city tiles where I wanted.  This would have "broken" the bathymetric data.  After doing this I realized that exact water depths might not be best for SC4, and did the rest with terraformer and in-game.  I imagine a whole different technique is needed for proper rivers, but my photo shop trial expired.  I wait for Gimp 1.8, which will apparently be able to handle 16bit.  (There is This 16bit support Patch, but I don't exactly understand how to use it.)