mkm28 at 2015-06-18 15:40:07:
In the external world, our man starts out confidently alone on his small sailboat, apparently on a journey that others considered ill-advised. We don't really know that much about him, but I personally find him to be arrogantly cocooned -- he thinks he's safe, surely he thinks he's going to succeed, but he's clearly not all that prepared, having relied too much on his GPS and other tech. He doesn't know what he doesn't know.
When his boat gets wrecked by an adrift container, he's forced to consider all these things. And as he loses all of these material things (technology, then the boat, then bits of the raft), he's forced to dig ever deeper into himself to see if he has the will to survive. The ultimate battle is between him and himself.
I hadn't thought about the human connection really until someone pointed it out in a previous post, but he starts out fractured from his presumed loved ones and is out on the water alone. He spends the entire movie alone, surviving on his own, but at the end, he has to take someone's hand, accept help from another, to ultimately survive. All may be lost, but no man is an island.