The speaker feels lost and is looking for someone who can't be found. The poem opens with drowning: darkness, no air, no way to struggle. Then it flips to flying, described as naïve and young, as if the speaker once felt free without noticing the danger. But the drowning never stops, and the two feelings sit side by side, which makes the speaker seem confused about whether they are rising or sinking.
The repeated "I can't find you" grows more desperate as the poem goes on. The image of one foot in the grave while the other strives for "an answer long gone" suggests someone caught between giving up and holding on, chasing something that may no longer exist. The "you" is never named, so it could be a person, a lost love, or even a part of the speaker's own self. The mood is heavy, anxious, and pleading. The final line turns it into a painful question: maybe the one being searched for doesn't want to be found.