1960s: "The Ugly Dachshund" - Formal (unvoluntary) pool-party
https://www.youtube.com/watch?v=PD-j3unpMlk

1970s: "The Great Alligator" - Underwater-escape-scene
https://www.youtube.com/watch?v=bufVpxtlF6I

1980s: "Alamo Bay" - Rain-scene
https://www.youtube.com/watch?v=frAYF1qvDw0

1990s "Paparazzi" - Clothed lady jumps in pool to join bathing men
https://www.youtube.com/watch?v=foKT1S-VuPM&t=190s

2000s: "The Tuxedo" - Pool-fight-scene
https://www.youtube.com/watch?v=U0AAWUDkR1I&t=60