Final answer:
The metaphor suggests the narrator's sense of freedom after the captain's death.
Step-by-step explanation:
The intended effect of the metaphor "It is some dream on the deck" is c. his sense of freedom after the hateful captain drowned. The metaphor suggests that the narrator feels a sense of relief and liberation now that the captain, who was likely oppressive or authoritarian, is gone. The word "dream" indicates that the narrator may have previously felt trapped or oppressed, and now feels like they are living in a dreamlike state of freedom.
Learn more about Effect of metaphor in poetry