[Yo-Yo]

If you assume that the damaged area is 14,000 square feet, and that the boat swung in a complete circle around the anchor during it's mooring, then:

A=πr²

Solving for r, the circle (boat plus anchor chain) need only be 66.8' long to sweep an area of 14,000 sq. ft.

[lefty-lie-spy]

Perfect. That is exactly what I wanted to see. I’m guessing that is what the port authority assumed too rather than tearing a big swath across the harbor.