Aquaman was the son of a marine scientist who discovered the ruins of an advanced civilization he believed to be Atlantis and studied their knowledge. By training and a hundred scientific secrets, Aquaman learned to draw oxygen from the water and become wonderfully strong and swift. After his father's death, Aquaman dedicated his life to continuing his father's research in the ruins and to protecting the sea from all who might abuse it.
Aquaman's base of operations was a palace in the ruins his father had discovered, converted to be water-tight and filled with air. Aquaman had a lot of equipment in the place, including a way to monitor surface news reports.
Aquaman learned to communicate with fish early on, and knew many sea creatures by name. One friend who stuck with him for awhile was Ark the sea lion, whose son Blackie caused Aquaman some grief.
While Aquaman was dedicated to stopping anyone who abused the power of the sea, his main recurring villain was Black Jack the Modern Pirate, who took advantage of the War to rob ships. Black Jack went from scheme to scheme, always foiled by Aquaman in the end.
Another crime-fighting friend during this time was the Sea Sleuth, Phineas Pike, whose attempts to be the sea-going version of Sherlock Holmes kept Aquaman busy.
This Aquaman is distinguished visually from the later Silver Age version of Aquaman mostly by his gloves, which were yellow instead of green. This Aquaman also was focused more on the sea-going humans of the world than any other threats, was frequently seen on shorelines around the world, and was a hero to any honest sailor.