This red-border Kodachrome slide (undated, but probably from the late 1950s) shows an underwater performer at Weeki Wachee Springs. She's holding food to attract fish in one hand, while she hangs on to the air hose that she uses for breathing in the other hand.

As Wikipedia explains, "Weeki Wachee Springs is a natural tourist attraction located in Weeki Wachee, Florida, where underwater performances by 'mermaids,' women wearing fish tails as well as other fancy outfits, can be viewed in an aquarium-like setting in the spring of the Weeki Wachee River."