During the recent lake draw-down, why did my neighbor permanently stake & tie 4 small white buoys (boat fenders) right next to the bank? ?

He's marking his territory, and it's easier with the water gone.

How would strangers on the internet know?

We don't even know what lake you're talking about.

Ask your neighbour.

Asking here makes as much sense as me asking you why my neighbour’s wife has so many male visitors whilst he’s at work.

everyone here knows your neighbor. he thinks you're an idiot. you're not helping us change his mind.