The Aquarena Center began as a hotel and theme park, which featured the famous “Ralph the swimming pig,” diving mermaids and glass bottom boat rides. The latter lived on when the university purchased Aquarena in 1994 and changed its focus from entertainment to preservation and education. Glass bottom boat tours are available daily from 10 a.m. to 5:30 p.m. The resort hotel now houses the River System Institute, a major facility devoted to the study and protection of Texas waters.