Hello Bored of the Rings,
Thank you for having the idea to create a project "without terrain".
That's a feature I am interested in.
I tested your first and third versions and as mentioned by 3Com, I can see the presence of a terrain under the water.
Personally, when I import a custom-made terrain, I push up the water level above the default terrain (position Y = 600) and in this way I can move in the water to climb on the imported terrain.
As you know, painting the built in terrain in GG Max editor consumes tons of megabytes and for the whole terrain (200x200 square meters), when you save your .fpm project, its total size could easily exceed 10 Gbytes only for that painted terrain.
When I read the title of your thread, I thought that you provided some project where the default terrain of GG Max editor was no more there.
I examined the content of your .fpm files to understand your workflow, but it is not clear in my mind.
Please could you explain what you mean by "without terrain" ?