How to choose the right dock lines?

What is Dock line?

Dock line secure your boat to a dock, or to another boat when rafting, either temporarily or semi-permanently. These applications demand different types of dock lines. We'll walk you through what to consider and help you make the right choice.
how to choose the right dock line?
Evevry single boat needs the dock lines.
Some boaters like to go to waterfront restaurants for a dock and lines, others rent a transient slip for a weekend getaway aboard, and still others choose in-water boat storage in a slip. In all of these very different cases, boaters share a common need for dock lines. Since dock lines are the only thing keeping your boat from drifting away and out to sea, we think it’s fair to say that choosing the best dock lines for your boat is a rather important decision.

Different between the materials

Polypropylene
Polypropylene degrades quickly in the sun, , Breaking strength is lower than Nylon. and has a low breaking strength. By. the way , it must be some advantages for , it Floats on the water. It is a good choice for the Jet ski, easy to dock the cleat with the speed boat or PWC. Highly recommend skiers have one/
Nylon
Nylon has three characteristics that make it ideal for dock lines. It is incredibly strong and durable. It is very stretchy, and it is very good at resisting sun, fuel and Chemical damage. And its breaking strength is higher than polypropylene.
Therefore, Nylon is the best material for dock lines.
We recommend Nylon for the speed boat , PWC. And the polypropylene for 
Jetski.

What size of dock lines do I need?

Thickness
We recommend your dock line should have 1/8" of diameter for every 9 feet of boat. And with the minimum size of 3/8", even your boat is 16 feet, please use 3/8" at least This means a 20' boat should use 3/8" lines. A 40' boat should use 5/8" line. You can use a bigger line and often boaters prefer this because a larger line is easier to grip and handle than a smaller line.
Dock Line Diameter
Typical Boat Lengths
3/8” (10 mm)
Up to 27ft
1/2” (13 mm)
28 ft – 36 ft
5/8” (16 mm)
37ft – 45 ft
Length
Basiclly, transient dock lines should be about 2/3 of the boat's length when used on the bow and stern. Spring lines should be equal to your boat's length. But we would spare some longer dockline for the boat because you never know what situation you will have in your boat life. (Use for towing or mooring)
In our opinion, you should have at least 2 dock line longer 10 feet than your boat's length. For example, your boat is 28 feet, you should have 2 pieces of 1/2"* 20' for the transient dock lines, 2 pieces of 1/2" x 25' for the spring lines, and 2 pieces of 1/2" x 35' for towing or mooring.

How Many Dock Lines Do I Need?

Keeping four to six dock lines handy is sufficient for most boaters. Four may also do the trick in some wet slips, though as we just mentioned, different wet slips can vary quite a bit. In some cases you’ll want spring lines in addition to bow and stern lines.
No matter what type of boater you are or what type of boat activities you enjoy, keeping docklines on hand is a must. Make sure you choose the best dock lines for your needs, and your days on the water will be that much more enjoyable.