The diver in "Diving into the Wreck" has an amazing, maybe even transcendental, experience underwater. Everything about the ocean world is fascinating, new, and intense. We aren't merely looking at nature in this poem, we are fully plunged into it. This poem is about exploring and changing and feeling, but on a simple level it's a story about how we come into contact with nature. What do we do when nature takes control? How do we interact with other creatures? Nature provides the setting, and the atmosphere of this poem.
This poem describes a journey toward unity with the natural world. At first the speaker feels awkward about being in the ocean, but gradually she evolves into a "mermaid" or "merman," a creature of the sea.