This is a 3D-animation I created from scratch as an university assignment. I'm not so happy with this one … the fish animation is pretty wobbly, the quality is not that great and the scene looks unreal overall. But I was a total beginner in 3D-sculpting/-animation before I started working on this, so it was still much work and I'm at least somewhat proud of it.
My computer's capacity was a severely limiting factor for this project. Even with my Intel Xeon E3-1231 CPU and my GTX 970 GPU, the processing of the water simulation and the rendering of the final product took days in the end. I had to compromise between rendering time and quality. I worked in the cycles engine, which resulted in the light artifacts (fireflies) that are especially visible on the water. For comparison, here's a single frame exported at a resolution of 1000 samples, which took three hours.
I built everything in that scene myself. Some of the textures I photographed myself and made seamless in Photoshop, the rest I took from textures.com.
Here's a couple of screenshots from the production process (which I hope are self-explanatory).