Here is the story:
https://www.foxnews.com/travel/campers-rescued-sos-water-bottle-waterfall
Basically they float down a river with inner tubes and get trapped above the last waterfall. Dad did the same thing seven years ago and was shocked to discover that the fixed rope he used seven years ago was no longer there and the water level was higher than before.
They get rescued after they stick a note in their nalgene bottom and toss it over the falls where some hikers find it and alert SAR.
ratagonia
an update shows that Dad brought a rope, but with the higher water he did not dare rappel in the flow.
And, there is already a thread about this…