Speaking of DC writers and artists of the 50s and 60s, by the way, I have a vague memory that one of them was famous in diving circles for designing some kind of underwater breathing apparatus; do you have any idea who this would have been Robbie?
Getting back on topic, here's an earlier Mike Western Valiant cover with an underwater theme:

And while I'm at it here's an Eagle cover that you've probably already seen (not sure about the artist but it could be Alex Oliphant):

...Personally I hope I never have to try out Jacques Cousteau's method for repelling sharks!
- Phil Rushton

