Determine the Rope's Diameter Based on Boat Size
Smaller boats (under 20 feet): Ropes with a diameter of 3/8 inch (10 mm) are usually sufficient for mooring or docking.
Medium boats (20–40 feet): Ropes in the range of 1/2 inch to 5/8 inch (12–16 mm) provide the necessary strength for handling increased loads.
Larger boats (over 40 feet): Use ropes with diameters of 3/4 inch (18 mm) or more to ensure safety and durability under heavy strain.