"JAXAshby" wrote in message
...
2) It serves as a shock absorber, helping to absorb the boat's movement
due
to the wave action.

you obviously do not understand the mathematics of catenaries. NOBODY
chains a
boat to a dock, or a rock on shore.

In a light wind, the chain is lying flat along the bottom. If a large wave
came along, the boat would have to tug the chain off the bottom. You get a
damping effect when you lift the chain from the bottom and remove the slack
from the line. You go from a parabolic shape in the rope and rode, to a
straight line shape. In order to do that, a lot of energy is expended.
Thus, the rode as as a shock absorber. Get it?