Silver Springs once had direct, nearby competitors, one of which distinguished itself with its “Scenic Submarine,” “America’s Most Unusual Boat Ride.” ¬†Until 1974, Rainbow Springs competed for the same tourists as its more famous counterpart thirty miles east in the same county in north-central Florida, as detailed in Tim Hollis’s Glass Bottom Boats and Mermaid Tails: Florida’s Tourist Springs. Originally called Blue Spring, Rainbow Springs got its name in the 1930s as part of an effort to attract tourists. The destination grew into the postwar years as the attraction added glass-bottomed boats and even submarine rides and staged underwater tableaux in much the same fashion as Silver Springs, historian Tom Berson’s “stop” on the “itinerary” of American Tourism: Constructing a National Tradition, due out…