Of course, coming out of the 1940s, Green Arrow was considered a bigger draw--he frequently appeared on the covers to More Fun Comics while Aquaman never did--and of course Tomahawk had his own title. But man I would have loved to see him in there instead of SK. *Sigh*
DC did a bajillion of these PSAs in from the later 1940s to the very early 1960s, and I find them utterly charming. If I had a scintilla of free time, I'd start a blog devoted just to them--who knows, even though they aren't Aqua-related I'll put one of them up here every so often, just so we can all learn something!