Just thought I'd share some ads, etc, that I came across. This one from Esquire Magazine, 1936 (Sorry it's so small! Click on it.):
From Life Magazine 1940; I don't believe I had ever heard of Skol. Hmmm, I think we all know by now what damage the sun can do!
Jantzen from 1950:
I like her pretty little swim dress on this old toffee tin - 40's or 50's?
Or perhaps you want to crochet your own plaid bikini and cover-up, like the ones modeled here by the lovely Shelley Hack and friend in 1975:
Or perhaps not.