[Ragnar]

I think 2015 are experimenting with different type of water-texture. To create good-looking computer-graphic water, some kind of a fresnel shader is required. This filter makes the water transparent depending on the angle you looks at it. If you take a closer look at Hells-Angles screenshot you can see the soldier hand beneath the surface.

As I guess you already know, the water is colorless. The color is made by the surroundings reflecting on the surface. In a gray day the water is gray, it is dark in stormy weather, and blue on a bright shiny day.

Some games use bumpmapping to create waves. This is a texture, which fools you to believe that there is more geometry in the water than there really is. It can be used on a single polygon and are very effective.

If you take another look at the screenshot, you will notice that something is wrong. There is no interference between the soldiers / objects and the water, just a strait cut. There should at least been some animated rings like those in Tomb-Rider together with the whitewater mentioned by Polaris.