The purpose of the dock line is to keep your boat in place while it is at the dock. If you are not familiar with dock lines, then you might think that strength is the only thing they need. However, this is just one of the several properties that you need to look for when browsing dock lines. In addition to being sturdy, a dock line also needs to be:

• Resistant to UV rays.
• Resistant to abrasion and rot.
• Preferably, it will be reinforced in specific areas that will be rubbing into other surfaces.

The last thing on the list is not mandatory, but it is something that you will often see if you opt to browse the top-end dock lines available on the market. So, what are dock lines made of?

What is the Material and Structure of a Dock Line?

Typically, they are made out of nylon. You can also choose from different thicknesses, but we would not advise you to go overboard – a 3/8″ line should be enough for your fishing boat. If you have any doubts, then do not hesitate to look at the detailed description of the dock line you are interested in. Usually, a 3/8″ double-braided dock line should be able to hold a maximum of 5,800 pounds. A good rule of thumb to follow when choosing a size is available below:

• For boats up to 20 feet – 3/8″.
• For boats between 20 and 30 feet – 1/2″.
• For boats between 30 and 40 feet – 5/8″.

Speaking of braids, there are several popular types of ‘construction’ used in dock lines. The double-braided ones are the most mainstream, but there are also three-strand twisted and mega braided dock lines. The latter is undoubtedly the most heavy-duty, consumer-rated dock line – it can typically hold up to 48,000 pounds. If you are the owner of a small boat, there is no point in looking any further than the double-braided models – they will work just fine. Not only are they the best bang for your buck, but they are much more convenient to handle compared to the stronger lines.

Often, boat owners hesitate between buying the double-braided or three-strand twisted line. Our advice can be summed up in several bullet points, assuming you are going for a 3/8″ model:

• Double-braided line is usually rated for approximately 5,000 lb. (vs. three-strand twisted line, rated around 3,000 lb.)
• The double-braided models are typically softer and, because of the way they are built, they will not harden over time.
• They are also more resistant to UV radiation.
• A double-braided one will rarely tangle.

Do Dock Lines Have Other Important Properties?

As we explained above, the primary things to look out for are the thickness and the type of dock line you are buying. Some models also have little extras that are certainly handy. Our suggestion is to go for a dock line that comes with a loop or an eye out of the factory – it saves a lot of time, and it is much more convenient to have it at your disposal instead of having to tie and untie knots constantly. Thankfully, most decent dock lines come with this feature, so you will not need to browse for long.

You might be tempted to match the color of your dock line with the one of your boat, but this might end up being messy if you opt to for a lighter-colored line. Of course, this is not a major issue, but I do suggest going with black lines – they will get dirty, and the dark color certainly makes the grime less noticeable.

If you’re looking to replace your dock lines, then the best set for most boats is going to be a set of 15′ black 3/8″ nylon lines with a 12″ loop. 

Anything Important to Know About Using Dock Lines?

There are many ways to tie a dock line, but you do not really need to do anything too fancy. We advise you to check out some video tutorials, which will show you the simplest ways to tie your line to the cleats on the dock and your boat. Typically, one of the simplest ways to do it is this:

1. Grab the end of the line, and wrap it around the bottom part of the cleat (full 360°)
2. Then, do a ‘figure eight’ by wrapping the line around the top part of the cleat, going through both ends.
3. Finally, hitch it to the cleat for extra safety.
4. Make sure to wrap the rest of the dock line and put it at the dock – don’t leave it hanging.

Are there Other Fabrics Available for Dock Lines?

Yes, there are other materials other than nylon available. If for some reason, you are interested in trying out dock lines made of a different material, I would have to encourage you not to get them. Not only are these difficult to find, but they can end up costing you thousands of dollars in repairs if they end up failing.

For example, you may come across rope made out of polypropylene, but it does not have the properties needed to replace a dock line. It is not nearly as strong as nylon, and it lacks elasticity and abrasion resistance. Even if it manages to get the job done, it will not last you for very long. Remember that the dock line serves a very important purpose, and you should compromise when it comes to quality.

You can find dock lines in cotton as well, but being an organic material rather than synthetic, it just will not last as long or be as reliable as nylon dock lines will be.

The last thing we want to mention when talking about dock lines is chaffing. This is inevitable, and it is bound to take its toll on the condition of your line. Typical dock lines are meant for temporary use, so they will last relatively long before you start seeing signs of wear and tear. However, if you are planning to purchase a more permanent dock line, then you need to go for a reinforced model. As we already mentioned above, permanent dock lines are either covered with chafe protection entirely, or specific sections of them are reinforced. You can also buy polyester chafe guards to further extend the lifespan of your dock line.