This is a variety of Fancy Knots done in 1/4" and 3/8" manila rope. There are Monkey's Fists, Globe Knots,
Rope Mats, Turk's Heads and a Bow fender, or Dolphin Fender, for a Dinghy.
Knob knots are an exercise in skill and perseverance.
Fender used on the Bow of a Boat.