N0 Case, N1 6CLC movement. 15mm case without crown. 10mm lugs.
I think Aqua Queen. Although, I haven't found an identical ad yet.
I have a completely identical ladies watch without the whale, however (except it's N5.) So that's throwing me off. That makes me almost want to call it a ladies Sea King because you know how they did with some of those Sea Kings. Some had the Whale and some didn't.
But I'm sticking with Aqua Queen for now. I could have sworn that I'd seen an ad some place for an Aqua Queen that looked like this one.
Edit - I found a 1972 Aqua Queen on this site that looks identical to this watch. It won't won't let me post the link, though. This is likely where I saw the ad, then.
Looking through the ads the only match I can find is the Aqua Queen. Here is the 1972 model we id'd, and here is a 1967 ad: