The tracker trails were surprisingly high above the water. Some were cut into the rocks, but others were wooden walkways suspended above the treacherous water held up by poles stuck into holes in the sheer cliffs. Large freight junks might require 300 - 400 trackers. The Yangtze used to be much more dangerous than it is today. In recent times many of the large obstructions have been blown up making the channel deeper and safer.
Today boats large and small are mostly all motor powered.
And long may we boatmen stop cursing our lots.