At the beginning of the poem, in the first stanza, the speaker mentions her early morning walk with her dog and refers to the sea as a "Basement": demonstrably unromantic images. She seems to see some ships upon the water, imagining that they think of her as a "Mouse." She personifies the "Frigates" by giving them the power to presume.
In the third stanza, she says that "no Man moved [her]—till the Tide / Went past [her] simple Shoe," personifying the ocean as a man and even as a potential lover. This man, the ocean, rises up over her legs and waist, even over her breasts underneath her "Boddice." She feels as though the ocean, "He," would "eat [her] up" as though she were a droplet of dew upon a dandelion; this is a simile. It would consume her. However, the comparison of the ocean to a man, as the water climbs her body and soaks through her clothing, seems somewhat sexual in nature.
In the end, however, she "start[s]" and he "follow[s]" her, filling her shoes "with Pearl," and then he "bow[ed]" and "withdrew" as she neared the town. This personification of the ocean as not only a man but an apparent suitor, as well as the repeated references to the speaker's body, combine to produce an underlying meaning for the reader: it is almost like a young woman wants to embark on a new romance, but when the man tries to rush her, she backs away from him, compelling him to withdraw. Perhaps the young woman does not want to be consumed, as an ocean would consume a drop of dew; perhaps she desires to keep her freedom and independence. It is difficult to escape the idea that the poem, in large part, is a metaphor for a relationship that was cut short.