There are many instances where the sea is personified, where it is described in human or animalistic terms. These uses of figures of speech give the sea (and nature in general) character, almost becoming like a character itself. The vivid descriptions also help to create the visual imagery of the situation. This is important to note because the correspondent and his boat-mates are struggling for their lives; in doing so, they are doing their best to manage the boat and doing their best to understand the sea. Therefore, the correspondent often personifies the sea (and the boat). Near the end of the story, the correspondent describes the situation:

The third wave moved forward, huge, furious, implacable. It fairly swallowed the dinghy, and almost simultaneously the men tumbled into the sea. 

The wave can not be "furious" because it is not conscious. It also won't "swallow" the boat because the sea is not a living thing with a mouth, etc.; such is the use of personification. The narrator gives these personifications and descriptions in order to give the sea this character of being like a person or an animal: wild, untamed, and powerful. The irony here is that the sea is inanimate. The narrator tries to give it a persona in order to have someone or something to be angry with. The men in the boat are frustrated that there is nothing to vent their frustrations against. Giving the sea a persona is an attempt to understand it. Note that the last sentence implies this: 

When it came night, the white waves paced to and fro in the moonlight, and the wind brought the sound of the great sea's voice to the men on the shore, and they felt that they could then be interpreters.