not like Cousteau with his assiduous team (line 8)
It isn't an accident that the name of a great explorer comes up in the first lines of this poem. When we come across this comparison, we begin to get a sense of what our speaker is doing. We already know that she is a diver, but people dive for different reasons. This could be a fishing trip, or just a pleasure cruise. But when Cousteau comes on the scene, we get a little whiff of excitement. If we're dealing with exploration then there is new stuff to see, daring acts, and maybe even some danger. What's even more interesting is that our speaker is not like Cousteau in the way she approaches diving.
I came to explore the wreck. (line 52)
Well, we probably couldn't ask Rich to lay it out any more clearly than that. The speaker is here to explore. All of the actions in the poem come from that idea: the looking around with the flashlight, the notes on the compass, the dead bodies, etc. We think that this line is meant to remind us of other kinds of exploring, and other kinds of wrecks. Whenever we go back to a place where a bad thing happened or remember a tragedy, we are doing a kind of exploring.
the thing I came for: the wreck and not the story of the wreck (lines 61-62)
These lines are about cutting through to the real thing. That's the essence of exploration. You aren't taking someone else's word for it. You are going to see for yourself, to verify what you have heard. This is almost always harder than sitting back and listening, but it has its rewards too. This is probably true of emotional disasters too. You can leave it underwater, you can try to bury it, but the real challenge, and the real progress comes when you start to do the work of exploration. Maybe you see this "wreck" in a different way, and that's great. We do think though, that poems offer a great way to talk and think about difficult and painful moments in our lives, and how we can deal with them.