"As I Ebb'd With the Ocean of Life" is not only the title, it's also the first line. While some poets are known for this as general practice, we'll assume here that Whitman meant for us to read the line twice. But why?
Well, the first few lines use anaphora to mimic the sound and action of waves, which wash ashore again and again. If you've ever spent any time studying it, you know that the ocean has a lot of repetition going on. So, having us read the title and then read it again as the first line, Whitman makes it sound like we are right where he wants us to be: standing with him on the seashore.
And what's more, the title and first line contain a lot of imagery that the poem uses over and over. The ocean is a metaphor, really, for all of nature and life. It's also the setting of the poem, as the speaker wanders the shore of his hometown, a place surrounded by the sea (check out "Setting" for more).
All in all, then, we'd say this is pretty appropriate title (and first line). Wouldn't you?