What does Yu Guangzhong's poem "river of no return" mean? What historical figures are mentioned in the poem?

which wave is the moon catcher? —————————————— Chang 'e

Which wave is the drowning doctor? ———————————— Qu Yuan

It's time for me to drag Li Sao ———————————— It's also Qu Yuan's (Li Sao)

curling Li Sao that drags me back to Qu Yuan

gurgling, and let me swim between stone quarries. Qu Yuan

Let the immortal river cleanse my sins for me. Thousands of feet's white hair is floating ————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————— Think of historical figures from historical records, and lament what they left by this river, and lament that this river has nourished the Chinese land and Chinese culture for thousands of years. No matter how history changes, she is still broad and inclusive. Therefore, going to Dajiangdong is to sigh with emotion.

The phrase "Bearded Su is still like Bearded Su hanging over the past" actually means Bearded Su Dongpo. The whole sentence means that I am here to remember the book Dongpo, just like Su Dongpo was here to reminisce about the past.