Buying guide for best dock lines

If you don’t want your boat to float away, you’re going to have to tie it to something solid. Chains are definitely strong enough for the job, but they’re heavy and don’t have any give or stretch to them. That means all the shock will be transmitted to either the cleats on the dock or the ones on your boat. That’s never a good idea because it will gradually work them loose. You need the right dock lines.

You need at least two kinds of dock lines for your boat: transient dock lines for use when you’re away from your regular dock or mooring and permanent dock lines for when your boat is in its usual dock. Using a different color for each will help you quickly distinguish between them. Dock lines also need to have some give or stretchiness to them, as well as good resistance to sun, weather, and water.

If you’re having difficulty deciding which rope is right for you, we’re here to help. Our buying guide can take you through the process of figuring out which dock line is best for your boat and your needs. Check out our favorites, too.

A cleat hitch resembles a figure eight with a third loop added. The rope doubles back under itself before you loop it the third time. This puts the long end of the rope over the tag end and anchors it in place.

Key considerations

Size

• Diameter: The size of the dock lines you buy will be determined by the size of your boat. The longer your boat, the larger the diameter of rope you need. Starting from a minimum of 3/8 inch in diameter, the general rule of thumb is an extra 1/8 inch in diameter for every 9 feet of boat length:

  • 3/8 inch: Boats up to 27 feet long

  • 7/16 inch: Boats 28 to 31 feet long

  • 1/2 inch: Boats 32 to 36 feet long

  • 5/8 inch: Boats 37 to 45 feet long

  • 3/4 inch: Boats 46 to 54 feet long

  • 7/8 inch: Boats 55 to 63 feet long

  • 1.0 inch: Boats 64 to 72 feet long
     

• Length: The length of your dock lines also depends on the size (length) of your boat, but in a different way:

  • Transient dock lines should be about two-thirds the length of your boat from bow to stern because you don’t know what kinds of cleats you’ll be tying up to or where they’ll be located. For example, if your boat is 18 feet long, you need a transient line that is 12 feet long.

  • Permanent dock lines, by contrast, are normally a bit shorter. They should be half to three-quarters of the length of your boat, preferably closer to half the length. If your boat is 18 feet long, your dock line should be 9 feet long.

Dock line features

Material

• Natural: Hemp is the most common natural material for rope. Natural materials tend to be heavier and weaker than synthetic fibers. They’re less resistant to abrasion and water absorption. With the advent of synthetic fibers, very few ropes are made of natural fibers any more unless they’re being used for decorative purposes.

• Nylon: This is the preferred material for ropes of all kinds. It’s the strongest material available, but it does lose around 15% of its strength when it gets wet. Be sure to factor this into your calculations about how much load you want your rope to withstand. It has good elasticity as well, which makes it good for dock lines. It is UV and abrasion resistant, but it doesn’t float.

• Polypropylene: Of all the synthetic fibers, polypropylene is the cheapest. It floats and is quite strong for its weight. It doesn’t have much resistance to UV rays, abrasion, or heat, If your ropes will be outside for extended periods of time, this isn’t the best material.

• Polyester: Polyester is nearly as strong as nylon, and it doesn’t lose any strength when it gets wet the way nylon does. It’s also highly resistant to UV rays, heat, and abrasion. It doesn’t have much elasticity, though. This will transmit more shock to the cleats on the dock and on your boat. It’s also expensive and generally not as easy to work with as nylon. Finally, knots in polyester ropes can be difficult to untie.

Braid

• Three-strand: A three-strand rope has a knobby appearance. It’s easy to splice. It’s also the least expensive.

• Double-braid: This rope is generally stronger for any given size, but it only stretches about half as much as a three-strand rope. On the other hand, it comes in more colors than three-strand rope.

• Mega-braid: This is a 12-strand, single-braid rope that is normally used for boats that are 70 feet long and more. It’s very supple and easy to handle, but it isn’t easy to splice. It only comes in black and white.

Color

Dock lines come in black, blue, green, tan or gold, and white. A number of ropes combine colors, such as red and black or green and white. Other colors may be available depending on the manufacturer. Color-coding the ropes on your boat by function is an excellent idea.

Eyelet

A number of ropes have an eyelet on one end. It’s a loop about 10 to 12 inches long for attaching the rope to a cleat on the dock. Not all ropes have them.

Dock line prices

Inexpensive: The low end of the price range for dock lines is under $10 for a short rope with a small diameter, typically 15 feet or less in length and 3/8 inch in diameter.

Mid-range: These dock lines cost from $10 to $20. They are 20 feet or longer and around 1/2 inch in diameter. Some have an eyelet or metal hook on the end.

Expensive: These dock lines, which cost $20 and more, are 25 feet long and 1/2 to 5/8 inch in diameter. Custom-length ropes over 25 feet long are more expensive.

Tips

• Store your dock line correctly. Coil up your dock line into a long loop. Hang it halfway over the lifeline on the edge of your boat. Pull one end of the loop back through itself and tighten it down. Your rope is now secure yet easily accessible when you need it.

• Toss a dock line correctly. When you’re throwing a dock line to another person, make two even coils of rope, one in each hand. Then with one hand, throw underhand to your target, like you’re bowling.

• Maintain your dock lines. Wash your dock lines with warm soapy water, a brush, and a hose every couple of months to prevent residue buildup.

• Keep your dock lines flexible. To reduce stiffness from repeated wetting and drying, put your dock lines in a pillowcase and wash them in a washing machine with extra fabric softener. Don’t put them in the dryer. Air-dry them instead.

Transient lines, which are used only occasionally, should be stored separately from your permanent dock lines. Keep them coiled inside a closed container where they won’t be mistaken for a dock line.

FAQ

Q. How often should I replace my dock lines?

A. Even with good care and maintenance, dock lines tend to accumulate a lot of gunk on them. Most boaters change their lines every two to three years.

Q. What is a chafe guard?

A. A chafe guard is a leather or canvas tube that surrounds the dock line where it goes through a boat or dock cleat. It helps reduce wear and tear on your dock line, especially fraying.

Q. Aside from length, what’s the main difference between transient and permanent dock lines?

A. A permanent dock line has a loop on one end so you can fasten it to a cleat. Transient lines don’t have this loop.