Chafe Protection For Boats and Why You Need It

Numerous problems affect boats. Sunlight, rain, bird droppings, mold and mildew; a slew of forces are constantly vying to rob your boat of its good condition. But there’s one force that wants to do your boat real harm. It’s a force that affects every boat kept in a slip or tied to a mooring, and it works its influence every minute of every day.

Chafe: The simple rubbing of your dock and mooring lines against other objects, even other lines. It’s happening all the time, whether you know it or not. Why? Boats reside in the water, and water is always moving. As the water moves even slightly, your boat moves independent of the dock or mooring, and this causes your dock and mooring lines to move as well. As they move, they rub against the cleats, chocks, fittings, and other objects that they are in constant contact with. This rubbing, day in and day out, slowly but surely wears into the line and eventually may compromise its strength of sever it altogether.

Lots of people seem to be willing to live with chafed lines, but there are several reasons why this is a bad idea. First, as chafe wears into a line, the line becomes weaker. While it may still be tied up and look intact, in reality it may be too weak to handle the next big storm. You may only realize this after the storm, when you return to your boat to find that the line has broken.  Another reason is cost. Dock and mooring lines aren’t cheap. Allowing them to chafe and wear probably means having to break down and replace them at least every couple of years, and this expense can really add up. Last but not least, chafed, worn lines can become a bit of an eyesore, and detract from the appearance of an otherwise well-kept boat.

Dock and mooring lines have two principal purposes: Keep your boat securely moored and absorb a certain amount of shock as your boat moves. Asking your lines to also handle chafe is just too much. The solution? Chafe protection! Simple, low-cost chafe guards can protect your lines from chafe and wear, allow them to maintain their integrity and strength, and can drastically decrease the frequency of line replacement, saving you money. The idea is simple: Position a chafe guard at each area of the line where wear and chafe occurs- generally at the cleats and chocks, but it can be anywhere the line rubs against another object or surface. This way the chafe guard wears and your line does not.

What Makes a Good Chafe Guard

There are numerous options for chafe protection, from various re-purposed materials to retail products. It’s important to note however that not all products and materials are created equal, and some work better than others. The ideal chafe guard is made of material that is resilient enough to withstand chafe for a long period of time. It’s flexible enough to fit into chocks and around cleats, won’t harm the surface it’s rubbing against (like a rubrail or gelcoat), and will allow water to pass through its surface and reach the line. That last attribute is pretty important, as I will explain below.

Obviously it’s important for a chafe guard to withstand chafe for a long period of time, but what is required to meet this need varies from place to place. Some marinas are more sheltered than others, and thus experience slower chafe. A relatively light material may be sufficient for a boat in one place, while a more heavy-duty material is required for a boat somewhere else.

Flexibility is sometimes overlooked, but it sometimes critical to the effectiveness of the chafe guard. A chafe guard that can flex and conform in an around chocks, cleats, and fittings is likely to stay in place more easily, keeping the protection where it’s needed.

A soft material is a good choice when the line rubs against gelcoat or a polished surface, as it will be less likely to leave marks or wear as it rubs those surfaces. After all, protecting your line is important, but leaving marks on the boat while doing it shouldn’t be necessary.

Finally, allowing water to pass through the chafe guard and reach the line underneath has been suggested to help the line stay cooler during the cycling brought on by severe weather, and may make the difference in keeping the line intact through the storm. A study published in July 1997 by researchers at the MIT(1) showed that nylon and polyester lines generally built up internal heat as they cycled through repeated stretching and contracting, as they would during a major storm event. The study found that this cycling causes friction between the fibers that make up a line, and this can build up so much heat that the line can fail from the inside out. The study also found that water, allowed to reach the line, can provide a certain amount of cooling and lubrication, decreasing internal friction and keeping the line intact.

Choices, Choices

So what is the best choice for chafe protection? From my experience, strong, woven synthetic textiles seem to provide the best mix of benefits, with very little if any issues. Unlined polyester fire hose jacket, tubular nylon webbing, and several retail chafe protection products provide this sort of construction. Some are thicker and more resilient than others, and some costlier than others. In general, they meet all of the requirements of the ideal chafe guard, and their synthetic nature make them resistant to mold and mildew, and most are highly UV resistant for longevity in the outdoors. 

With any chafe protection, it is important to know that not even the best or highest-priced materials will last forever. It’s important to inspect your lines and chafe guards each time your visit your boat. A good method of maintenance is to periodically reposition your chafe guards slightly, to evenly distribute wear over their surface and extend their useful life. And when it comes time to replace the chafe guard, you can rest comfortably knowing that you are replacing an inexpensive chafe guard, rather than the entire expensive line.

A Word About PVC or Vinyl Tubing

PVC / Vinyl tubing remains a very popular choice for do-it-yourselfers looking for low cost chafe protection. It’s readily available and relatively cheap. It also has a pretty long history of use, and has worked for many people. There are several very important reasons why I don’t recommend PVC / vinyl tubing though, and here they are: First, these materials are very stiff. This makes the tubing hard to fit into chocks and around cleats. This stiffness also requires that the tubing be pretty tight to the line or well-tied in place, otherwise it can tend to resist bending and work its way out of place, especially when used at a chock. Lastly, PVC / vinyl is completely waterproof and will prevent water from reaching the line during severe weather.

In Closing

Chafe affects every boat, everywhere, but the solution is simple and cost-effective. Chafe protection provides your boat the safety and security it deserves, and gains you peace of mind. Low-cost chafe guards, either purchased or improvised, can extend the life of your dock lines and save you considerable money over the long term, all the while providing assurance that your lines will endure and keep your boat secure. Don’t wait until a dock line breaks and leaves your boat bouncing around your slip. Install some chafe guards today and start enjoying the benefits now!



(1) Seo, M. et al. “Wear and Fatigue of Nylon and Polyester Mooring Lines.” Textile Research Journal vol. 67 no. 7 (1997): 467-480. Print.

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