In "The Sea," Reeves uses an extended metaphor to compare the sea to a hungry dog. In the first stanza, the dog sits on the beach and gnaws at the stones that tumble in on the water while making a moaning noise. The sea's churning of stones and the shore is likened to a hungry dog chewing on bones. In the second stanza, the dog howls at night and shakes his sides over the cliff. The sea's fury at night, when waves pound the cliff with great force and noise, is compared to a large dog shaking its wet sides. In the third and final stanza, when a day in May or June is so calm that not even the grasses stir, the dog sits down on the beach with his head on his hands and sleeps. A quiet day is compared to a dog sleeping so peacefully that he does not even snore.

This poem begins with great energy. In the first stanza, the sea is "tumbling, rumbling," allowing the reader to imagine the sound and motion of the sea with imagery. In the second stanza, the sea is also full of fury, as it roars, much like a dog howls. Imagery helps the reader imagine the sound and sight of the sea at night. In the final stanza, the sea is calm, as conveyed by phrases such as "reedy tune." The repetition of "so quiet" in the last line emphasizes the quiet note on which this poem ends.

James Reeves (1909–1978) was an English poet and writer, many of whose works reflect an interest in the English countryside. He wrote many poems and stories for children as well as for adults. "The Sea" reflects a tradition of English verse for children that also includes the work of Edward Lear and Lewis Carroll and that often engages the fantastic or whimsical.

It consists of three stanzas of different lengths using frequent end-rhymes but in irregular patterns. The rhythmical pattern of the poem is also irregular.

The poem is written in the third person and in the present tense. It consists of an extended metaphor comparing the sea to a dog. It posits the sea as having three different moods, one corresponding to a hungry dog, one to a restless dog, and one to a peaceful resting dog. 

One distinctive feature of the poem is its emphasis on the sounds of the sea. Many evocative terms and types of onomatopoeia are used to convey the variety of different sounds made by the sea.