Aquaman is a superhero. His powers are to be Michael Phelps and talk to fish.
Paul Norris and Mort Weisinger, after losing a bet, created Aquaman. He debuted in November of 1941. A month later, Japan attacked Pearl Harbor. I'll leave you to put two and two together. Initially, Aquaman was a normal human. As a child, his father taught him how to breathe under water and communicate with fish, which was a perfectly normal thing that happened all the time in the 1940s. We can't do it anymore thanks to global warming and legalized abortions. He did this at the bottom of the ocean, presumably to make his son tougher, making him the worst little league dad ever. For the rest of the 40s and 50s, Aquaman fought Nazi U-Boat Captains, modern day pirates, and uncut plastic six pack rings.
The founding members of the North American Man Cephalopod Love Associtaion.
Aquaman in the Golden Age also supported sexual relations between humans and sea life and was an outspoken opponent of caviar, or as he called it "mass aquatic abortions." More info on this can be found by researching the case of (Fish) Roe v. Wade. Zing!!
Beginning in 1959, Aquaman's persona, history, powers, and origin story were revised in a failed attempt to make him a valid superhero. In his new continuity, Aquaman was the son of a lighthouse worker named Tom Curry and Atlanna, an outcast from The underwater city of Atlantis. As a youth using the name Arthur Curry, he discovered that he had all the same powers he had for the last twenty years. How convenient. Arthur decided to use his powers to defend the oceans of Earth. Around this time, Aquaman was given his own 30 minute animated series as part of The Superman/Aquaman Hour of Adventure. (for more on the better half of this combo, read the topic page on Superman)
In his animated series, Aquaman only had one arm, and he used it to punch himself in the spine.
The 60's also brought about a new weakness to Aquaman, because apparently being a watered down and chest hair deficient version of David Hasselhoff was not enough of a weakness. This new weakness meant that Aquaman would die if he was not in contact with water once every hour. Thankfully, due to the number of people who routinely spit on Aquaman for being such a ridiculous excuse for a legitimate hero, he was never in much danger.
Now, at some point in the 60s, a number of comic book executives decided that it would be a great idea to have all these adult heroes start dragging around a teenage liability because child labor laws don't seem to apply as long as you slap knee high boots and a mask on a little boy. Aquaman's future social service problem was an orphaned Atlantean boy dubbed Aqualad.
"No more tricks" says Aquaman as they share an octopus moustache ride.
Later on, Aquaman was voted King of Atlantis, mostly due his ability to control the minds of things that lived in the ocean, and married an Atlantean woman named Mera for the same reason.
1985's Crisis On Infinite Earths brought about the Modern Age of Comics and with it was another retooling of Aquaman's history, and once again it failed to make him cool. In this new retelling, Aquaman was named Orin and was the son of Atlanna, Queen of Atlantis and the sorcerer Atlan but was cast out because he was blonde and Atlanteans are Bizarro Nazi's like that. The stories of Aquaman detailed a life wherein he was outcast, lived on his own, got a woman pregnant, discovered he had an evil twin brother/sorcerer, and just about everything else that also happened on season one of Dawson's Creek. Then the early 90s hit the world and Aquaman attached himself firmly to the grunge scene by growing a beard and cutting off his left hand to replace it with a hook.
Mr. Smee, bring me the head of Peter Pan.
Eventually the hook was replaced by the Lady of The Lake, yes the same one that gave Excalibur to King Arthur, who gave Aquaman the Waterbearer Hand. Her publicist insists that she has no comment on the matter. The new hand gave him all kinds of crazy magical abilities like dehydrating someone, changing his density to make him sink, and the ability to heal him of all the emotional wounds dealt to him by witty pop culture satirists such as myself. The next time he was seen, he essentially made a deal with a big evil type to save millions of lives and prove that Spider-Man was a whiny little emo bitch for doing so only to save a very old woman. Then he was killed (and there was much rejoicing...Yea!). His son, who initially showed good sense in disliking his father, still took on the mantle of Aquaman and continued a legacy of loserdom not seen since Captain Boomerang.
Creators took the Aquaman stories in a new direction, away from the usual comic book hero stories and more into sword and magic fantasy because they thought "Hey, wouldn't Lord of The Rings be awesome if it happened underwater." didn't sound retarded to them.
For a time, the CW network, known for its combination of awful teen dramas and even more awful teen dramas, contemplated the development of a live-action Aquaman series but later cancelled the project, forever proving that Aquaman is such a shitty character that he's not even good enough to be aired alongside the fucking Gossip Girl.