In the summer of 1959, for the dedication of the new Submarine ride attraction at Disneyland, the opening ceremonies had eight live actress mermaids performing a synchronized swimming ballet in the lagoon. They also frolicked underwater to the delight of eager guests peering from the submarine portholes. Earlier that day, four of the mermaids appeared on a special float in the Main Street parade where they tossed strands of pearls from King Neptune’s treasure chests to guests gathered on the curbs as King Neptune sat in a giant shell throne at the front of the float.
In 1965, to celebrate the 10th anniversary of Disneyland, the mermaids returned to the lagoon for the summer. The guest reaction was so positive that, the following summer, a new set of mermaids took up residence in the lagoon. Apparently, that was the last season for the mermaids although there have been claims of other live action mermaid sightings in later years.