First of all thank for you great mod. I really like the height of these walls. Its so helpful.
But I have this gap between wall and ground. Maybe I did something wrong? And the texture of the wall differs with screenshots here...

Issue with a gap between wall and ground
Try turning them 180º.
I tried to turn it 180, but the gap is still here. Seems that your wall model for 1x2 grid, but in game it uses 2x2. I have no ability to move this wall closer to remove a gap.

What you need then is 1 tile piece, right?
I mean it would be better to move the wall in the grid to avoid these gaps. Its just visual issue. If compare with vanila wall, it takes 2x4 tiles. But the wall model have size 2x4 too (i'm speaking about X dimension). So your wall takes 2x2 tiles, but the model have size 1x2. Sorry if its a bit annoying stuff, just want to help make your mod better :)
Oh y understand you now, well you have to take as reference and squares that are drawn by the game.
The reason for 1x2 tiles is to make the corner and cross models look different to the vanila ones.
Ill have to build on a 2x2 space all possibilities straight, corner, cross and tee models.
The vanilla models (sorry Mafi) look ugly (corners, etc.) xDDD
It make sense about grid. But these gaps. Ohhh 😂
Im working on it , changed textures and models they where causing problems with shadows, y also discovered allready the issue
with the leaks, it seams that, the straight parts doesn't finish correctly connection with corners and other pieces.
Investigation before releasing new walls. They will be now able to be build inside ocean, too.