Conversation so far:
When did the Golden Age begin for Aquaman?
For Aquaman, the Golden Age began in November 1941
What happened with Aquaman in #73?
Aquaman's first origin story was presented in flashback from his debut in More Fun Comics #73
Who was Aquaman's father?
Aquaman's father was a famous undersea explorer
What was Aquaman's father's name?
His father's name is not given, but Aquaman says If I spoke his name, you would recognize it.“
What did Aquaman's father do?
His father was a famous undersea explorer
What city did Aquaman's father discover?
He discovered the underwater city of Atlantis
What did Aquaman's father find there?
He found books and records of the people of Atlantis' marvelous wisdom
Did Aquaman's father find any particular records or devices in Atlantis?
His father found and studied records about how to draw oxygen from the water, and use all the power of the sea to make someone a strong and swift swimmer
Is this how Aquaman got his powers?
Yes; Aquaman's father used the knowledge from the records of Atlantis to train Aquaman's powers

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