Can’t be his son, there’s at least a 200 year gap (if not a bit more). I do think that Hook might have been in the Navy for Eric’s kingdom, (the buildings in the background in Good Form seem to match buildings in Ariel), but there has to be a few generations in between Hook’s King and Eric. And it’s not like Hook’s Naval past is common knowledge. So I don’t see how Ariel would make that connection (assuming the connection exists).