Sea World and Marine World were big time destinations for families in the 70s. Maybe it had some to do with the popularity at the time of Jaques Cousteau. But the shows were great. Waterskiing elephants were hard to beat. Orcas jumping for fish and giving their trainers rides and splashing spectators.
Last time I took my family to Sea World was 2009 and the shows were boring and the attendance was weak.