In stephens cranes to the maiden why does sailor view sea as dead grey walls on which is written grim hatred of nature?

The sailor in Stephen Crane's "To the Maiden" views the sea as "dead grey walls" because he perceives the sea as a barrier that separates him from his loved ones on land. The sea becomes a symbol of the harsh and unforgiving elements that keep the sailor away from his home. The "grim hatred of nature" that the sailor reads in the sea is his own bitterness and resentment towards the forces that keep him separated from his loved ones.