They are imposing creatures, standing more than waist high - these are not small birds. They have a regal bearing. As you approach, they watch you, turning slowly to follow your movement. If you slow down, you can get within perhaps 10 feet or a little less. But eventually, the heron will decide you have invaded the royal personal space. Reluctantly, it will slowly stalk away. And by slowly, I mean: One. Step. Every. Five. Seconds. All grace, and the very picture of offended royalty.
If you move too quickly, or if there is no place to retreat to with dignity intact, the heron will squat down with those backward bending knees, and leap into the air while unfurling its huge wings (6-7 foot wingspan, and more than a foot of chord). There will be perhaps one flap, and the bird will glide to the next dock fully in ground effect, wingtips brushing the surface of the water. And it will display its displeasure with a loud "Graakkk!" (Really - that's the only way I can describe it - it is a really prehistoric sound - not something you'd associate with a song bird - or any bird for that matter. It sounds like... umm... a dinosaur.)
This fellow was looking for dinner in the water off our dock. I don't think he noticed us inside the boat (or maybe he was just pretending to not notice). Now, the dock surface is about 2 feet off the water, so he had a long reach. He would squat down, and stretcchh out his long neck, sticking his butt in the air. The obvious outcome was predictable: he fell in, headfirst. There was a great thrashing, and the big wings lifted him out of the water with a single pump. Then he was standing on the dock again, saying, "What? Did something happen here? Huh? Me? No. You are mistaken."
But he did quit fishing here.