I wasn't sure where to put this post.
I made a water effect with refraction, using only built-in effects.
<img src="https://dl.dropboxusercontent.com/u/28087823/Construct%20Examples/Water%20Refraction/Html/screenshot.png" border="0">
What I used:
1. an animated sprite of Perlin Noise (24 frames at 48x48pixels, made seamless in photoshop, frame by frame, with the Filter->Offset method) inside a semitransparent layer with the "Lens" effect.
2. a caustics sprite set on "dodge"
3. a semitransparent greenish tiledBackground set to hard light (to set the color of the water and everything in it)
4. a semitransparent water "surface" sprite
So it's tileable refractive water, that can affect all layers beneath it, and doesn't use masking or "force own texture" on layer. This is something that can't be reproduced any other way in Construct 2, so far as I know.
You can check the effect out here:
live demo
and you can study the CAPX here (although a little sloppy):
CAPX
EDIT: Also the principle behind surface reflection. Read more on the second page of this thread.
Reflection CAPX
Reflection Live Demo