Not at all stupid! He looks like he is destroying the bridge! I still remember thinking his name was Sub-Mariner (pronounced, or so I thought, Sub-mah-reen-er).
I think Subby was the first (or one of the first) characters to tread the line between good guy and bad guy. He's certainly the oldest one still around. Batman treaded the line too, but he is a couple months younger.
It may sound stupid but until I bought my first copy of this book, years ago, I thought Subby was destroying the bridge! I had read the reprints of Marvel Mystery #9 and I knew Subby was bad; I didn't realize he'd become a good guy until I bought Timelys that had not been reprinted. Aw, the ignorance of youth!