Dock Lines

How To Choose the Right Dock Line and Mooring Rope

General rule - the length of bow and stern lines should equal two thirds of boat length. Spring lines should be longer, approximately the same length as your yacht or 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,stern line,bow 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.

Boats | under 20 feet | use 3/8" line:
20 feet to 30 ------------feet use 1/2" line
30 feet to 40 ------------feet use 5/8" line
40 feet to 70 ------------feet use 3/4" line
70 feet to 90 ------------feet use 7/8" line
90 feet to 110 -----------feet use 1" line
110 feet to 130----------feet use 1-1/8" line
130 feet to 150 ---------feet use 1-1/4" line
150 feet to 180 ---------feet use 1-1/2" line
180 feet to 200 ---------feet use 1-3/4" line

By choosing of line for your boat, keep in mind that 12-strand 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 20%. Make your choice accordingly!

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

Be sure to use proper chafe protection where dock and mooring lines may rub on chocks, hawse pipes, gunwales or docks. Constant chafing on one area of the line for prolonged periods is a mooring rope's worst enemy.

Ballistic nylon tubing, leather or urethane dips are available for chafe protection if required.

Docklines Vs mooring lines

Designed specifically for mooring lines, Dockline delivers 15-18% more strength than 3 strand mooring lines, and is available in many colors to compliment hull color.


• Abrasion resistant polyester cover
• Shock absorbing braided nylon core
• Stronger than 3-strand ropes
• Easy to handle and splice

3-Strand Polyester Docklines

Even when wet this polyester line retains full strength and remains easy to handle.
It can be used for anchor warps, lanyards, mooring warps, boat fenders and fender lines.


• No strength loss when wet
• Good abrasion resistance
• Easy to splice with soft eyes, nylon,
stainless steel or galvanized thimbles
• Flexible and soft to handle

Multiplait & 12 Strand Nylon

The flexibility of multiplait nylon makes it easy to stow in the chain locker without
kinking.These ropes are designed for anchor warps, mooring warps and mooring risers.

• Elasticity with flexibility
• Absorbs high shock loads
• Stows neatly
• Easily spliced – featuring special markers for splicing

3-Strand Nylon Docklines

3-strand nylon has a high stretch dockline characteristic that makes it exceptionally
best at absorbing shock loads.

• Perfect for anchor warps and mooring lines
• Absorbs shock loads
• Easy to splice with soft eyes, stainless steel, nylon or galvanized thimbles

Mooring lines

When picking up a mooring make sure you clear any unnecessary lines from the foredeck before making your approach. Also make sure the bow chocks/fairleads and mooring cleats are free. If you’re unsure of the strength of the wind and current make a practice pass and aim the boat to one side of the pick-up float to make it easier for the crew.

On craft with a high freeboard it maybe easier to "lasso" the buoy rather than have a crew member grappling with the boat hook. Hook the rope pendant under the float, not the float itself.When the eye splice of the mooring rope is over the cleat lash it in position with the pendant from the buoy using figure of eight turns and a half hitch.

Always inspect your lines regularly for any signs of wear.
Nylon has excellent shock absorbing characteristics but areas vulnerable to chafe should be protected with a piece of tough rubber hose or leather


Before entering or leaving a marina always prepare your lines well in advance, making sure there are no knots or kinks in the rope. Also the skipper should always check that the crew has the right line for the right job and isn’t
going to leave someone struggling with over-long lengths of warp or get caught short!
Always take into account what wind and tide are doing when making your approach or before casting off. In light wind conditions the use of a boat hook may be an easier option than rigging slip lines when leaving the dock. Use free running ends for slip lines – knots and splices can jam.

When leaving, let go the slack lines first – these are the ones that aren’t doing anything.
When sharing a cleat or bollard with another line rig your ropes so that either line can be cast off without disturbing the other line.To do this run your line up through the bight already in place, then drop your eye over the cleat/bollard.
When sailing short-handed run a line ashore around a bollard or cleat then make it fast back on board. This means lines can be tended from the boat not the pier.


Get the best warp such as a Marlow Multiplait for use with the anchor. More than any other line for use afloat this is probably the most important investment you’ll
make – the whole boat will depend on the quality of the anchor rode and how you rig it. Not only is the best line safer, it is easier to handle. Long lengths of inferior rode are very difficult to handle.

Nylon is ideal at absorbing shock loads but remember when selecting the size of line that nylon will have some strength reduction when wet.To improve chafe resistance and protect your ropes fit the smoothest, widest radius chocks/fairleads you can. Also, where possible, fit cleats close to chocks/fairleads. Rubber snubbers also help reduce the shock on the line and protect boat fittings.
Have enough line on board to provide a scope of at least 7 x the max depth of water expected. In heavy weather when the boat is pitching and tugging at the scope, 10 x the depth of water may be needed. A good catenary angle keeps the anchor on the seabed and helps it dig in.
A taut cable might jerk the anchor free of its holding. It is also advisable to have a length of chain between the anchor and rode to increase weight on the bottom and
keep the anchor flukes at a low angle. Chain on the seabed also extends the life of your rode by protecting it against rocky bottoms.

Back to Index of parts - Anchoring and Docking

Here you can find the vast choices of marine manufacturer/products from major brand "Anchoring & Docking" for your boating life including:

  • Bruce Anchors, Boat-Boating anchors
  • Danforth Anchors, Boat-Boating anchors
  • dock lines
  • Edson Boat-Marine Parts, Boarding Steps
  • Fortress - Fortress Marine Anchors
  • ice eaters
  • Imtra, Boat - Marine parts and accessories, anchoring systems
  • Boat-Marine Anchor and Dock Products, Manufacturers
  • installing anchors, info
  • Lewmar - Steering Systems & Anchoring
  • lewmar Latest Catalogue
  • lewmar anchors
  • FAB Dock - minimal maintenance and mobile dry docking boat systems

  • Good practices and tips - Docking in the wind.

    Knowing these things and taking your time will make docking in the wind and current much easier.

    Connect-A-Dock's - Floating docks & Different Dock-applications, Manufacturers