Exploration is the activity that takes place in this poem. Whatever else the speaker is doing or feeling or saying, she is diving down into the ocean to explore. We are used to this idea of exploring a shipwreck. Whether it's videos of the sunken Titanic or stories about diving for pirate gold, we know about people in wet suits looking at old ships. What this poem suggests, though, is that exploration might not just refer to looking at a ship. There might be other kinds of emotional, internal exploration going on here.
This is a poem about "seeing for yourself." The point of most expeditions is to report back, to prove something. Here the speaker is confronting the facts of her own life, and the lessons she learns are completely personal.