Bill Everett returned to the theme of water-based heroes  a few times over the course of his long career. Along with the Sub-Mariner and the Fin, there was also Hydroman, who could turn himself into water.

Unfortunately, in the well-entrenched fanboy world where every, simply everyone, who is hipper than the room knows, just knows, that Aquaman is a complete lame-oid, such characters are left to rust.