This is a great example of how even a good sized Alligator is hard to see. He was probably 5 feet (1.5 m) in length, an educated guess since was under water. Also he was almost on the bank, you can see the leaves that fell off the trees.
I like this shot because his eye is crisp and clear. They have incredible, almost evil, eyes.
I just a few minutes some people walked down this trail talking and he silently slipped under water. Not a ripple as only an Alligator can do.