What To Look For When Buying Dock Lines
Your dock line must be a nylon rope. Polypropylene breaks down and rots quickly in the sun, it doesn't have the level of stretch needed, and has a low breaking strength so it is generally a bad choice. Dock lines most commonly come in three weave types: three-strand, braided, and double braided. There are slight differences in each rope, but all will make sufficient dock line choices.
- Braided Nylon: Stronger, easy on the hands and looks good.
- Double Braided Nylon: Strongest, easy to handle, abrasion resistant, and controlled elongation and looks great.
- American Made vs. Import: Double braided nylon American made rope is 100% nylon, in contrast, some import rope may only have a nylon outer jacket and cotton core.
Many people will add a snubber into their dock line to help take the stress off the dock lines when the tides rise and fall or there are consistent incoming wakes.
Here is an image of how you would attach a bungee dock line with hooks as a snubber.
Dock lines come in a variety of colors. Many people like to match their boat, while others like high visibility ropes so they can always see them. The other benefit of high visibility dock lines is you don't leave the while still tied to the cleat.
What Size, Length, and Quantity Of Dock Line Do You Need?
Your dock line should have 1/8" of diameter for every 9' of boat with a minimum size of 3/8". This means a 20' boat should use 3/8" lines. A 40' boat should use 5/8" line.
As you can see, there are many different types of dock lines for your boat. It is beneficial to research the difference and see which line works best for your boating activities.
(Remember to inspect your boat lines and dock ties and replace as needed. Boat lines and dock ties weather and weaken over time.)