My Captain does not answer, his lips are pale and still; (17)
It's interesting that the speaker pays attention to the captain's lips in this moment. Do you think that's a natural place to focus on? After all, still, pale lips are a pretty good sign of death. Or does this suggest something more than platonic male bonding on the part of the speaker?
My father does not feel my arm, he has no pulse or will; (18)
Although the captain isn’t actually the speaker’s father (as far as we know), the relationship between the father and the son may be the most precious and desired bond for Whitman. The fact that death interrupts this bond is really just a terrific bummer.