Mermaids have had a long history in narrative. From fairy tales to contemporary films, they have captivated the cultural imagination as simultaneously enchanting and dangerous. The most well-known mermaid in literature was the titular protagonist of Hans Christian Anderson's The Little Mermaid. In Anderson's famous story, a young mermaid falls in love with a prince. She seeks his reciprocal devotion in order to become human (and obtain an immortal soul) but is unable to leave the water because of her fishtail. A "sea witch" offers her a potion that allows her to grow legs, but takes away her tongue and voice. The mermaid is successful in capturing the prince's affection but, at the last moment during their wedding ceremony, is required to stab him with a knife to ensure her survival. She finds herself unable to do so, and thus transforms back into a mermaid and melts into foam. Many of these major details were altered in the Disney film adaptation.
Anderson's mermaid is notably similar to the German Undine myth, which tells the story of a sea nymph who has to wed a human to gain possession of an immortal soul. In Scotland, these creatures are often referred to as selkies. What these, and many other stories like them, have in common is a reading of these mermaids as liminal creatures, existing in a precarious halfway state between woman and beast. Their relationship to the world of humans is similarly fraught. While Anderson's mermaid sees the potential for love and salvation on land, her attempts to gain these things cause her suffering and, eventually, her death. In other versions of this story, the mermaid lures a prince or sailor to a watery demise. The implication often appears to be that there is no simple coexistence between these beings. In this way, mermaids are often seen as trapped in an in-between state, unable to access a life on the shore but discontent to spend their time solely at sea. The tragedy in these stories often seems inevitable from the beginning.
In the context of Dickinson's poem, the brief appearance of mermaids is a signal to the reader that there is more to things than appearances would suggest. Beneath the speaker's initial perception of this sight as wondrous, there lurks something more dangerous. In making this allusion so early in the work, Dickinson sets off the reader's expectations of a more fraught narrative. It is quickly clear that this will not be a peaceful trip to the beach.
