Thanks to Captain Frank Lecardo, Owner & Instructor, Naples School of Boating, for submitting this article. The Naples School of Boating specializes in providing on-water training for new and inexperienced boaters and those who want to enhance their existing skills.
Dock lines are ropes used to secure a boat to a dock. They keep the boat in place, prevent it from drifting, and help absorb shock from waves and wind. Choosing the right size, type, and placement of docking lines is critical for both long-term and temporary mooring. This post will explore the different types of dock lines available and how to choose the right ones for your boat based on their intended use.
A primary consideration factor when choosing a dock line is the duration of its use. Is it being used on your permanent dock or as a temporary line when tying up at a restaurant, transient dock, or another brief scenario where you will be docked only briefly?
Permanent Dock Lines Considerations
Your permanent lines should always be the strongest and highest quality line that will fit on your cleats. They will last longer and provide you with maximum peace of mind when a storm hits. Also, your permanent dock lines should be protected against chafe. Chafing occurs when your dock lines continually rub against a surface that causes the lines to wear or deteriorate.
Types of Dock Lines
There are two basic types of dock lines for you to choose from:
- Three-strand Dock Line is the most basic and most affordable choice and ideal for temporary or transient dock lines that you carry onboard your boat.
- Double-braid Dock Line—is stronger, has less stretch than three-strand line, and is available in a wide assortment of colors to match your boat.
Whether you choose three-strand or double-braid, choose nylon lines because they are stronger and have more elasticity. Elasticity is an important consideration, as it helps absorb shocks when wind and waves cause abrupt movement of your boat.
Docking Line Size by Boat Length: Complete Guide
Logically, larger boats require a larger diameter dock line. The chart below provides a handy guide.
| Boat Length | Up to 27' | 28'-31' | 32'-36' | 37'-45' | 46'-54' | 55'-63' | 64'-72' |
| Dock Line Diameter | 3/8" | 7/16" | 1/2" | 5/8" | 3/4" | 7/8" | 1" |
Quick Glossary of Terms
To ensure our dock line placement information is clear, we've included the definitions of three critically important terms—bow line, stern line, and spring line.
Bow Line
The bow line runs from a cleat or chock and over the forward gunwale, where the line should be fitted with a chafe guard.
Stern Line
The stern line is attached to the stern tying fixture that is closest to the dock.
Spring Lines
There are two types of spring lines: forward springs and aft springs. The name of a spring line refers to which direction it is traveling when leaving the boat. A forward spring travels from the stern forward from one-half to one-third of the vessel length before being secured to the dock.
On the other hand, an aft spring line travels from the bow or forward gunwale back to the dock with a length about half the vessel's length.
Dock Line Placement and Spring Line Configuration
If you're wondering how to secure your boat, start by using bow and stern lines to keep the boat parallel to the dock. Then add spring lines to prevent it from moving forward or backward. Think of it like anchoring your boat in place on all sides.
Bow and Stern Lines
Keep the boat parallel to the dock and prevent it from drifting outward away from the dock.
Spring Lines
Prevent the boat from drifting forward or aft and, coupled with the bow and stern lines, keep the boat in its desired location.
Quick Summary: Choosing the Right Dock Lines
- Choose dock lines based on boat size and usage type.
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Use three-strand nylon for temporary use and double-braid nylon for permanent dock lines.
Match dock line diameter to your boat length using the sizing chart. - Use spring lines to prevent your boat from shifting forward or backward.
- Always protect against chafe using guards on all high-friction contact points.
Preventing Chafe
Chafe is caused by the continual rubbing of lines against surfaces such as chocks and cleats or against pilings and docks that your boat is moored to. While chafing cannot be completely prevented, it can be greatly reduced by using chafe guards in critical positions.
Where should you place chafe guards? Place them wherever dock line will rub against chocks, cleats, docks, pilings, or other dock lines.
Frequently Asked Dock Line Questions
What is a spring line for boats?
A spring line is a dock line that runs diagonally from either the bow or stern to a dock cleat. It helps prevent the boat from moving forward or backward while docked.
How long should dock lines be?
Dock lines should generally be 2/3 the length of your boat for bow and stern lines, and equal to the full length of your boat for spring lines.
What is the recommended docking line size?
Use 3/8" diameter for boats up to 27', 7/16" for boats 28'–31', and up to 1" for boats over 64'. Larger diameter lines resist wear and absorb more shock.
What are docking spring lines used for?
Docking spring lines prevent a boat from moving fore and aft at the dock. Together with bow and stern lines, they hold the vessel securely in place.
4 comments
[…] Quote from the source: … […]
If you are looking for the best ropes for boats then ropes from World of Watersports are a good candidate. This 60-foot rope measures 5/8 inches in diameter and is built with 16 strands, so I’m confident it’s strong enough to pull a 4-person spool even in rough waters.
The essential features of the best dock lines are strength for securing my boat and flexibility to make tight knots. Thus, my boat won’t go astray. I can also expect resistance against harsh outdoor elements, weathering, and loads from these excellent dock lines.
The explanation regarding the placement and definition of dock lines was well presented. Appreciate the diagrams showing each placement and the purpose of each application.