In the Silver Age, it became a popular theme to experiment with creating a female version of a popular male hero. Some of those characters are still around today, in one form or another; Batwoman, Batgirl, Supergirl...
But how many of you remember the original Aquagirl?
Aquaman rescues a girl from drowning, only to discover that she can't drown. Which is news to her, too.
After a series of field tests to determine the limits of young Lisa's aquatic powers and a hasty interview with the young lady's folks, Aquaman is completely baffled as to how Lisa can perform the same sort of aquatic feats as The Sea King.
Stopping by the next day to see how Lisa is doing. Aquaman gets an unwanted surprise
Geez, Arthur, try not to be such a dick! No wonder you live alone in a cave at the bottom of the sea. But hey, Aquaman is right. Superheroing is no business for amateurs. I mean, just look at the kinds of serious situations a seafaring superbeing runs into on a daily basis:
Thank God Aquaman was there! If he hadn't stopped by with Topo, poor Oswald may have had to wait for a passing shipload of T.G.I.Friday's servers!
Later, on patrol, Aquagirl suddenly siezes up and is no longer able to breathe underwater. Aquaman rushes her to the surface, where he explains to her about her mysterious new powers:
Whew! That was a close one! Aquaman almost got saddled with having to share his realm with a beautiful young woman. Now he can go home with his octopus and cry himself to sleep. After all, the ocean is made up of the tears of lonely Aquamen.