Successful distress signal - note in bottle

This family trapped in a gorge in California was found in a few hours after the distress note they put in a water bottle and dropped in the river was found downstream.

News article and video here:

https://abc7.com/message-in-a-bottle-helps-rescue-family-trapped-on-camping-trip/5530901/

That was certainly resourceful thinking and improvisation of available resources. But according to the story I saw about their plight, they were stranded because they expected a rope to be in place that would have allowed them to descend.

Bad idea on several fronts. What is the condition of a rope "left in place" for any length of time? Far better to carry your own rope, one whose history you know and anchor this rope in a way you know will be secure.

Of course, perhaps they could have just turned around and retraced their steps....