The Return

Ok, so here's what's what, I'm torn on this movie's interpretation, so let's get the basic stuff out of the way. First the "visual quotes" from Tarkovsky. Water is the defining element to this film, bordering on the obsessive. The sight of it, the sounds of it, the water's movement all create the perpetual water motif in The Return, the movie involves itself with so much water that by the end of the film even the audience feels just a little soggy. Whether this is a concrete metaphor or more of a Tarkovsky-esque nature theme is a little hard to discern, the water could be a metaphor for emotion, possibly fear or sadness in particular. It may also be an emulation for those emotions already being experienced by the main character Ivan. Then again, it could just be water.
Now, moving on to the father. This character is enigmatic, on one hand his cruelty to his sons is inexcusable, but on the other he seems to have squeezed 12 years worth of parenting into the course of a few days. Keeping in mind the end sequence when Ivan and Andrei must drag their father's body back to the car, all the skills they use from the point of the father's death are from lessons he himself taught them. Even certain lines of dialogue are used in refrain, like "with our little hands". It is obvious that the father did not nurture his sons on their journey (which was really just his journey, although we don't know for what, suggesting possibly that parenting his children was the last phase of his journey and he was meant to die), but he did instill them, however harshly, with certain values that resonate at the end of the film once the boys have to fend for themselves. So even though he was the biggest ass-hole dad of all time, he was still a dad.