In Chapter 5 of Literary Theory, Johnathan Culler discusses how poetry and rhetoric are quite similar and yet very different in that poetry, while it uses rhetoric through the use of rhetorical figures and techniques (such as metaphor and metonymy), is more artistic and is used to evoke emotions of the reader.
One rhetorical technique that I have seen being used in Diving into the Wreck by Adrienne Rich is metaphor. Specifically, stanzas 6 and 7 which talk about the diver finally finding the wreck after swimming through the sea. I found the use of metaphor in these stanzas interesting because it was used in subtle ways to bring up the idea of how stories/myths can be remembered or forgotten throughout the course of history, whether by accident or on purpose.