Why is my water invisible from certain angles?

I’ve made a water material that looks rather good, except close to the camera at certain angles… where it turns invisible. I suspect this is either an opacity, a depth fade or a refraction issue, but I’ve been unable to figure out which. I’ve tried to change values, change nodes, and searched on this site for clues. No luck so far.

Here are some screenshots of the material blueprint and what it looks like in-game:
1: the blueprint
2: the guy is standing in water but it doesn’t show
3: strange stuff
4: the water looks good from this angle

I’ve looked through it a bit more, and found that significantly lowering the fade distance in the depth fade (which affects both color and opacity) makes the water more visible. Still not perfect though.

The water looks completely transparent from some angles, which is why it disappears. But in real water - even if it’s clear - you can see what’s beneath the surface and what’s above it, like on this dolphin. I’m not talking about the splash effect. There’s a line of sorts, where the water surface is:

…while in my game, it looks like the water is simply not there. So the question is how to get that “line”.

The issue was not with the fade distance as such, but that the depth fade starts at completely transparent. I “solved” it by adding a semi-transparent greenish texture. It works, but feels a bit like cheating. I’m keeping it like this for now.

(edit: the geenish texture is added to both color and opacity.)