Choosing Dock Lines

Choosing the Right Dock Line & Mooring Rope

As a general rule, the length of bow and stern lines should equal two-thirds of your boat’s overall length. Spring lines should be slightly longer, approximately the same length as your boat. Spring lines keep the boat snugly near the dock by preventing it from moving fore or aft, while allowing for the rise and fall of the tide. Keep in mind; the position of cleats on your boat and dock may affect the length of the dockline.

Unless your boat is unusually heavy or will be subjected to severe conditions, a bow line, stern line, and two spring lines are recommended. If your permanent slip has outboard pilings as well, you will need an additional bow and stern line.

When making a choice of line for your boat, keep in mind that 12-strand (Mega Braid or Brait) line is not as strong as double braid line and colored line is not as strong as white line. Different braids have different attributes and tensile strengths can vary by as much as 15%. Make your choice accordingly.

Nylon for Dock & Mooring Lines

Rope inc. recommends using nylon rope for dock and mooring lines; the stretch characteristics of nylon absorb shock and will resist damaging cleats on your boat and on your dock. Nylon is available in 3-strand or twisted line, 8-strand, 12-strand or Mega Braid and in a double braid or yacht braid.

Our dock and mooring lines are made to order, are professionally spliced and the bitter end is hand whipped to prevent the line from unraveling.

Chafe Protection

Be sure to use proper chafe protection where dock and mooring lines may rub on chocks, gunwales, hawse pipes or docks. Constant chafing on one area of the line for prolonged periods is a mooring rope’s worst enemy; it can quickly wear, melt or cut through in adverse conditions. Ballistic nylon (Cordura) tubing, leather or urethane dips are available for chafe protection if required.

Our dock and mooring lines are made to order, are professionally spliced and the bitter end is hand whipped to prevent the line from unraveling.

Size (Feet)Suggested Line
20 and underGenerally use 3/8″
20 to 301/2″
30 to 405/8″
40 to 703/4″
70 to 907/8″
90 to 1101″
110 to 1301 1/8″
130 to 1501 1/4″
150 to 1801 1/2″
180 to 2001 3/4″

If your boat is heavier than average, or has greater windage, or is docked where it is subjected to surge, you should choose the next larger size.