Aquanaut? Aqualung? Aquaman?

I guess this is different from the time when Ian Anderson (of Jethro Tull) lived for an entire week under the surface of a primordial pond, using only his flute to breathe.

And how is aquaman a superhero? Reminds me of The State, and a skit where he gets made fun of by Flash, Batman, Superman, and Wonder Woman. Classic.