A Winning Lineup
The Right Lines Add to Your Boating Pleasure

When you tie up to the dock, anchor far away from the daily grind, or engage in the joys of watersports, the well-being of your boat and crew depend on the integrity of the lines (ropes).

Selecting dock and anchor lines for your boat can be an intimidating experience, with dozens of colors, sizes, construction and materials from which to choose, not to mention trying to determine price versus value.
If we approach line selection systematically, distilling the information into easily digestible pieces, deciding what lines are the best for your application shouldn’t be too time-consuming.

Sail vs. Power
For the sails and rigging, sailboats use ropes with outstanding strength, and low stretch factors. These are the super ropes, made with top-secret high-modulus composite fibers and names sounding like something from a science fiction movie. Great products, but not what we’re looking for – let’s keep shopping.

Motorboat Lines
On a powerboat, the primary purposes of the lines are securing the boat to the dock, ensuring the anchor rode and the vessel doesn’t separate, and for pulling inflatables/skiers. Therefore, we need lines that are sufficiently muscular to do the job, yet have a certain degree of elasticity.

Nylon
Nylon is very popular for dock and anchor lines, because of nylon’s excellent strength when wet, its ability to absorb shock loads, and abrasion resistance.

There are a couple of types of nylon lines dominating the market. The first, three-strand twisted nylon, is a trio of nylon ropes wound together to make a single line (see cutaway illustration below). This family of nylon line is a staple of the marine industry due to its relatively low cost and reliability. Three-strand nylon line is standard issue in Yamaha’s Boat Anchor Kits – an indisputable vote of confidence.

Double braid nylon lines feature a braided nylon core encased in a braided nylon outer cover, with the load shared between the core and the cover (see image below). The outer cover also protects the core from abrasion and damage from exposure to ultraviolet radiation. Stronger than three-strand nylon lines, double braid lines are available in a variety of colors to complement your boat.

Polyester
Double braid polyester lines are another option for dock and anchor lines. Retaining their higher load ratings longer than comparable nylon lines, double braid polyesters are also more resistant to abrasion than nylon; although the polyester products don’t possess the same degree of elasticity as nylon lines.

While using the lines, the double braid polyester lines seem to feel better in the hand than nylon lines. A subjective observation, but if you do a lot of line handling, this could be important on a long cruise.

Polyester/Nylon Double Braid
Then we have double braid lines with a nylon core surrounded by a polyester cover, so the line combines the stretch of nylon and the durability of polyester for a superior marine rope.

Polypropylene Rope
The cool thing about polypropylene rope is that it floats. Not as tough as nylon or polyester, there is a place for polypropylene line in the marine marketplace. Most of us know this type of line as a water towrope, but depending on the braid, polypropylene ropes make decent dock lines – at a reasonable price (see image below).

Dock and Anchor Line Miscellaneous
Dock lines should have about a 12-inch eye splice on one end, and the other end sealed or otherwise finished to prevent fraying (see image below).
Recommended dock line sizes:
Up to 25 feet: 3/8 inches
25 to 35 feet: 1/2 inches
35 to 45 feet: 5/8 inches
45 to 55 feet: 3/4 inches

Recommended dock line lengths:
Bow Lines: 1 1/2 x Beam
Spring Lines: 3/4 x Length Overall
Stern Lines: 1 1/2 to 2 x Beam

Anchor lines ought to have a thimble spliced securely in one end, and properly finished on the other end of the line.

Recommended anchor line sizes:
Up to 25 feet: 3/8 inches
25 to 35 feet: 1/2 inches
35 to 45 feet: 5/8 inches
45 to 55 feet: 3/4 inches

Recommended anchor line lengths:
No pat answers here, just remember to have enough anchor line (rode) aboard to have a 7:1 scope when you set the anchor. For instance, if you plan to anchor in 50 feet of water in moderate weather, you’ll need 350 feet of anchor line (7 x 50 = 350) to secure the anchor, while allowing the boat to move with the motion of the seas.

Tying Up Loose Ends
Buy the best dock and anchor lines you can afford. Too much is riding on whether your lines are up to taking on Mother Nature; it would be a shame to ruin an otherwise perfect day of boating because of a line failure. Y

Image Credits
Buccaneer Rope
Kwik Tek, Inc.
Lee Boyt
Samson® Rope
Yale Cordage