The style of The Rime of the Ancient Mariner is fairly typical of 18th-century Romantic poetry in several ways. Firstly, Romantic poetry is known for expansive descriptions of nature. Coleridge provides many natural descriptions throughout the poem, but here is a key example from Part I:
Listen, Stranger! Mist and Snow,
And it grew wond'rous cauld:
And Ice mast-high came floating by
As green as Emerauld.
Here, the speaker emphasizes the beautiful jewel-like quality of the ice and the weather that is so cold it seems unbelievable and "wond'rous." Natural features are prominently featured throughout the rest of the poem in the form of the sun, the moon, and the ocean. Most notably, a group of magical water-snakes inspire the Mariner to change his mind about nature. By making nature a point of emphasis, this poem shows its power and beauty (as well as the consequences one might face if one interferes with it).
Another important characteristic of Romanticism is a focus on the human psyche. In The Rime of the Ancient Mariner, this appears in a few ways, including in the fascination of the Wedding Guest with the Mariner's "glittering eye", his captivation by the Mariner's story, and his delayed attendance of the wedding. It also appears in the Mariner's psychological shift from casual indifference (and even cruelty) toward nature to an epiphanic realization of his appreciation of nature.
Many stylistic elements support these portrayals, including symbolism, allusion, and repetition, which enhance the poem's exploration of human guilt, redemption, and the interconnectedness of human lives with one another and with nature. With all of these elements, this poem had a great influence on poets of the Romantic Movement, especially in the subgenre of lyrical ballads.