The main idea of the poem is mourning the death of a fallen captain.
The third stanza is intended to acknowledge and accept that the captain is gone.
The following lines from the poem are emphasized with alliteration: "While follow eyes the steady keel," "The ship is anchor'd safe and sound," "Rise up—for you the flag is flung," and "From fearful trip, the victor ship."
If this poem were turned into a film, it would include more descriptive imagery and may emphasize certain words more than others. It is possible that it would also include sound effects.