The biggest one I ever saw was a mere eight feet long. Most are thick shoestrings. On one occasion I was chased around my front yard by a Bahamian boa. Well, that was my take on it. My wife and others who laughed their heads off at the spectacle swore that as the snake changed direction, I changed direction too - staying in front of it.
Bahamian snakes are totally innocuous.
Unless you're a chicken. They are called fowl snakes for good reason but pose no problem to human beings with a healthy heart. Twice in a row last summer I had a coil of rope drop on my head as I opened my garden shed door. Of course, it wasn't rope - it was snake. In my enlightened senior years I just nodded it off my head and watched it slither away - far more upset over the encounter than I was.