Fabulous Florida Springs- Ocala Area SILVER SPRINGS Kayakers paddling the Silver River look as if they’re floating on air. From a glass-bottom boat, I gaze down into the depths of Mammoth Spring. Just take a boat ride. Glass-bottom boats were invented at Silver Springs in the 1870s, and the tours are still the most popular activity at the park. A first-magnitude spring―one of the largest in the United States―gushes 550 million gallons a day.