Ok I've got this file in my archive, it's by Lynn and Bill Lyons. Seing that you've already moved your slider to max. I can only guess what went wrong.
If you followed these instructions: 2. Unzip the file InstlWat.zip directly into your main fs2004 folder. ...then this could be causing problems. But not all is lost if you install the bitmaps manually.
Before you do that though, just doublecheck that WinZip or whatever you are using didn't erroneously put the 'Texture' folder inside the 'Texture' folder.
I see that you have the right path: FS9\scenery\world\texture --- just make sure that the 13 bitmaps from fs9wat.zip ended up in the right location. It's possible that the folder which contains those bitmaps was placed in its entirety into the 'texture' folder.
Open the texture folder in your FS9\scenery\world\texture archive and look for all files starting with env_ .
If you only have 11 of those files, that means the installation wasn't successful. Back up those 11 files (they are the original, default bitmaps) and copy/paste the 13 bitmaps from fs9wat.zip into this folder. Try again and let us know how you're getting on.
Note: There are also flights in the .zip file. Unless you want to do those flights, you can just ignore those files and discard them.