Yes, Aquaman was once Aqua-Boy.

And what did the aspiring Aquaman wear while training seahorses, head-butting oil tankers, and hurling environmentally negligent CEOs into schools of voracious sharks?

Why, he wore the Aquaman Classic Costume Juvenile T-Shirt, of course.

Made from 100% cotton, this Aquaman costume t-shirt for kids is a comic-accurate simulation of Arthur Curry's bright orange torso-wear including illustrated scales and musculature, a bright yellow and screen-printed belt, and a hint of those classic green trunks.

Yes, this Aquaman costume top for juvenile-sized Aqua-kids allows one to enact revenge on the surface world from one's bedroom (which is comfortably situated above sea level).