We were at a camp nearby and saw loons on the lake behaving in a similar manner. But it does seem unusual for them to be in the same spot for hours and hours. I agree with White Maxx about staying away they are a protected endangered species.
I would stay clear of the entire area. Listen tonight for calls. Tomorrow you can dial the loon center directly and they'll know what to do, if anything. Thanks for your attentiveness! If you believe that the bird is in real distress, you can call department of fish and game any hour. They're very dedicated!
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