I grew up with these types of suits. The wet suit was pretty warm if it was thick enough. In Oregon we wore 1/4 inch thick neoprene. I liked the skin-one-side suits that I needed to use corn starch to get into. Phisohex soap is not good to use, as it has ingredients in it which probably are not good to keep on the skin--
hexiclorophene. I used phisohex soap to clean wounds when in the U.S. Air Force, as it is a disinfectant; it was part of our medical kits. But with corn starch, you slide into these suits very easily, and because they were only stitched on one side, they were waterproof at the seals. The best for warmth had no zippers, and were pull-over suits. Some had a short upside-down zipper in the chest, which allowed easier entry and still stayed warm.
The yellow stripes you see are actually seam tape, used to ensure that the seams did not part (before nylon lining and sewn seams). They also look pretty nice in the water too. Cousteau made a study and determined the yellow was the most visible color to use for his divers. They did use silver too, but I like the yellow strips better than the silver. I once had a silver suit, but it was so stiff I had to return it to the manufacturer after just a diver or two (one day of diving).
Here is a photo of me in one of these suits in Clear Lake, Oregon in the 1970s.
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SeaRat