I am a die-hard boater, and even in cold weather, you will often find me on my boat. Often, as I walk down my dock, I find that I am the only one there. While many boat owners leave their boats in the water during the winter months, a good percentage tie them up in the fall and do not return until warm weather comes back.
Because of this, I make it a point to walk the dock, checking lines and fenders on all the boats to ensure there are no issues. I know some of my dock neighbors who visit during the winter months do the same. One thing I consistently notice is that many boats do not have the proper lines securing them to the dock.
Your lines should not be ignored. Using the right type and size is essential to ensure the security of your vessel, passengers, and others at the dock.
Let’s take a look at what types of lines should be used for various purposes on your boat.
Dock lines
Nylon is the best material for dock lines because it is strong and stretches. Stretch is important because it allows the line to absorb the shock of the boat pulling on it in rough weather. Three-strand nylon is the least expensive option and works well. It is also easy to splice if you want to do so yourself.
Braided nylon is a bit more expensive. It is easier to coil, looks better to most people, and is stronger, though it does not stretch quite as much. Splicing braided nylon is quite difficult, so most people choose to preorder it in the needed lengths rather than splicing it themselves.
One common mistake many boat owners make is purchasing dock lines that are too small in diameter. A 3/8-inch line is cheaper than a 5/8-inch line, but if it snaps during a storm because it was too small to hold your 40-foot boat, saving $50 on a set of dock lines will suddenly seem trivial. Spend a little more now for the right lines, and you’ll sleep better at night.
The chart below shows the proper size nylon line to use based on the size of your boat:
Boat length Nylon line size
Up to 27 feet 3/8”
Up to 36 feet 1/2”
Up to 45 feet 5/8”
Up to 54 feet 3/4”
If the cleats on your boat are large enough, consider purchasing lines one size above the required minimum size. This is especially important if your boat is heavier than most or has more windage. It’s a small price to pay for extra insurance. Also, check your lines often. If they are frayed or worn, replace them.
Anchor rope
Assuming you are not using all chain, nylon is the best material for your anchor line (also known as rode) for the same reasons it is best used for dock lines: strength and its ability to stretch. Having the right size anchor line is just as important as having the right size dock line.
The rule of thumb is that your anchor line should have 1/8 inch of thickness per 9 feet of boat. For example, if your boat is 27 feet long, your minimum anchor line diameter should be at least 3/8 inch. Additionally, having at least 10 feet of chain between your anchor and the line is highly recommended to make anchoring more efficient and effective.
If you have a windlass, ensure you use a rope/chain size that fits it. If you have the proper windlass for your boat, it will accept the correct size rode for your vessel.
Towables and throwables
Lines for towables and throwables include any line used for towing inflatable toys, attaching to life rings, or towing other boats. For these applications, you should use polypropylene rope because it floats. It is much easier for a swimmer in the water to grab a floating line, and it is less likely to get hung up in your running gear since it stays visible on the water’s surface. Nylon rope can be used for these applications, but it does not float and may not be as effective. It could also render your vessel inoperable if it gets wrapped around your gear.
If you are considering towing a boat, know that polypropylene line is not as strong as nylon, so you will need a much larger line to safely tow even a small boat (as much as 3/4-inch diameter for a 22-foot boat). If you do not have the proper equipment or are unsure how to do it, it is better to leave the job to the experts.
Do yourself a favor this offseason: check all your lines and make sure you have the right ones for your boat.
