Once believed to be mermaids, docile manatees are now an endangered species. In winter, when ocean temperatures drop, they flock to the heated water discharged from Tampa Bay's power plant. From the observation platform, visitors can watch the marine mammals bask in the warm water, enjoying a respite from the cool bay. An educational building, complete with mini-theater, instructs visitors on the habits and lives of manatees while outside, nature trails wind along the banks and through picnic areas. Vending machines are available on the premises, and a gift shop sells related merchandise. Excursions generally take 1.5 to 2 hours.