A speaker looks back on a lover whose eyes pulled them under like the sea. The central image is simple: the beloved's eyes are the ocean, and the speaker is the one who gets swallowed. What makes it work is the way the poem admits both sides of the attraction. The eyes are beautiful in a way "people wouldn't understand," which suggests a private, hard-to-explain kind of love, but they are also dangerous, with an allure that feels beyond reach.
The speaker doesn't fight it. "I let them consume" shows a choice, not an accident, and the repeated "sinking and sinking" makes the fall feel slow and endless. The final lines turn the drowning into a compliment: being destroyed by this person was the "most beautiful way" to go. The mood is dreamy, a little sad, and tender, with a sense of surrender. The speaker seems to feel no regret, only awe at how completely they were taken.