"Water Plane" vs. "Lakes", "Rivers", & Creeks" (regarding water depth)

The title says most of what I'm driving at so I'll just dive in and get right to it:

In East Coast, USA and I'm sure lots of other places I haven't investigated quite yet, it is possible to use the detachable (Shift + C) camera, in order to skim and scour along the bottom of the river, (like a virtual BeamNG Plecostomus); and see the water that you're in suddenly disappear. It then looks like a dry river bed with perfectly dry air all around you, and blue skies and green tree tops above you.

This to me makes absolutely no sense... because if you're at the bottom of the deep ocean layer... (the "water plane" as World Editor calls it)… there is no cheating and diving down deep enough to suddenly see it disappear. If you're in it... you're in it!

Yet river, lake, and creek assets seem to excuse themselves from this obvious law of physics. And if you go into the z-position of creek, river, or lake asset; and raise the surface of the water 50m... you also raise the bottom of the water 50m into the sky... so that it appears suspended with dry air underneath it. Strange to say the least.

Is this normal, and is there a way to stop it from happening? Is there a way to raise the surface level of a river, creek, or lake, without erroneously raising the bottom of it off its bed by the same amount? Beside z-position control I was hoping there was an attribute for "thickness" control... so that you could raise surface level, but force the base of the body of water to stay on the river/creek/lake bed where it belongs. That way you could never accidentally see "clear dry air" underneath the water, skimming the indi-camera along the bottom of the body of water.

Picture examples below:

1. Captain Nemo's 1975 Ford LTD. It magically runs underwater without hydro locking. More importantly, we're seeing it submerged with water all around the car and the camera... as we should.


2. The car has been driven forward to the point, where it has gotten just deep enough, that it is below the base of the water property and appears to be on a dry river bed. The camera however is raised just high enough above the bed, that you can start to see just a slice of the water surface above the car.


3. With the detached camera laying on the river bed, behind the car, there is no ability to see the water, and the car appears to be totally dry docked (as Maine enters its 15th year of cataclysmic drought). Yet the water is very much above it right now... you just can't see it from below.


4. This water river normally defaults at z-position=19m, but let's raise it to 100m in the World editor just to see what happens. We can see odd streaks of what is the water from below, but nothing that looks like water per-say. Other than that, the car still appears to be basking in the sunshine.


5. Most odd of all, camera above the water with z=100m, and you can clearly see the surface of the water rushing by above the ground, yet it appears to have no depth or thickness, looking at it laterally from the side and down. Meanwhile... Captain Nemo's Fabulous Ford LTD is still parched and dying of thirst as we speak.


Unlike the "water plane" attribute that controls the master depth of the ocean... and if you raise its level, it knows to break lateral containment and flood what's around it; why do rivers, creeks, and lakes only occupy their fixed lateral footprint and not spread out, as you raise the surface height? This seems to be a problem. Can anyone explain this shortcoming to me? Thanks.

[Oh... and might I add, this has nothing to do with loading an outdated mod like the LTD. This still happens even if I open the program in safe mode and load a default vehicle.]