Conversation so far:
When did the Golden Age begin?
Aquaman's first origin story was presented in flashback from his debut in More Fun Comics #73 (November 1941).
What happened in #73?
The story must start with my father, a famous undersea explorer.
Who was his father?
if I spoke his name, you would recognize it.
What was his father's name?
CANNOTANSWER.
What did his father do?
His greatest discovery was an ancient city, in the depths where no other diver had ever penetrated.
What city did he discover?
My father believed it was the lost kingdom of Atlantis.
What did he find there?
records and devices of the race's marvelous wisdom.
Any particular records or devices?
he learned ways of teaching me to live under the ocean.
Is this how Aquaman got his powers?
By training and a hundred scientific secrets, I became what you see--a human being who lives and thrives under the water.

Question: What were his powers in the Golden Age?
Self-contained rewrite: What were Aquaman's powers in the Golden Age?