Hi Storebror, thank you again.
I've downloaded Carsmaster's water and now water under Graphic Extender looks as nice as always.
If anyone is interested, I've built a little JSGME mod to easily activate-deactivate Carsmaster water. Just created a folder in BATMODS called 'BAT Carsmaster Water for Graphic Extender', and made four subfolders (#DOF3, #JTW3, #TGA3 and #WAW3). In each of these subfolders, I made a 'MAPMODS' folder. Extracted Carsmaster's water into a safe place and copy the 'Maps' folder included there into every MAPMODS folder that I had previously created.
Now, all artifacts I had seen on water have disappeared. However, I've seen some little flaws and surprises.
In three random maps I've found the lines described by PO_MAK_249RIP:
Stalingrad Summer by cyberolas: a very subtle line is seen in the red oval. It is more noticeable when moving.

The Aleutians by agracier: more lines forming a grid.

Makin Atoll by 1C/Maddox: thicker lines on the island.

Flying on the Aleutians map, I found a strange, not-from-this-world structure:

An F-16 was sent to investigate:

It seemed like a cyclopean wall built by some forgotten civilization, or maybe some alien visitors. The 'wall' was located just at the bottom left corner of the map.

Definitely, that wall was not a terrestrial construction. Even with paused game, the cascade-looking wall was moving downwards.
Orders were sent to the F-16 to turn back home...

But it was too late. Some kind of energy barrier made contact with the F-16 and it was immediately disintegrated. No remains were ever founded.


Anyway, congratulations for this incredible WIP project.