My niece is looking for a movie/series from the 70s/80s about a family who is stranded at sea and they collect rainwater and learn to filter it into clean drinking water. She saw this when she was in the 6th grade so its been a while. She is 31 now, so you get the time line. Thanks in advance!
Sounds like The Swiss Family Robinson. There are a few different versions, including a miniseries. She probably saw the one from 1960
Maybe “Voyage of the Mimi”