The Blind Dude

Let's see if we can come up with some viable interpretations of pp. 242-256.  Analyze the conversation between Pi and the other person he miraculously encounters on the ocean when he is at his lowest point in his journey.  Consider the following:

Who is Pi speaking to?  At first he thinks it's Richard Parker (p.246), but then he thinks it's a random Frenchman (p. 248), but then the voice claims he's merely an "echo" (p.248) and he just happens to also be blind. And then, because R.P. "amply supped on him, including his face" (255), Pi "never saw who [his] brother was" (255-6).

What is going on in his scene?