Treatments to Preserve Ropes and Lines through the Seasons


More sailors in colder climates are finding ways to extend their sailing season through the winter, and we’ve provided a ton of research on tools, clothes, and measures sailors can take to ensure that chilly months are trouble-free. One of those measures is protecting ropes and lines against freezing as they become saturated with water that later freezes.

While testers were endlessly scrubbing ropes for Practical Sailor’s article on the best line-cleaning methods (see “What’s the Best Way to Clean Marine Rope”), we became interested aftermarket rope treatments—like fabric softener or water repellents—to improve line handleability, reduce water-weight gain and strength loss, and to prevent lines from freezing in colder climates. Do these treatments work? Can they damage the lines? Would any performance improvement be lasting in a marine environment?

We also wondered whether any treatment would keep aging lines from squeaking as they run over blocks under high strain. The noise is primarily the result of the loss of the rope’s spinning lubricants and can be indicative of deterioration of the rope in general. We wondered if both fabric softener and waterproofing treatments had the potential to replenish rope’s internal lubrication.

Although fabric softener certainly won’t hurt anything, we didn’t see any measurable improvement. Skip it. You should also not waste time waterproofing anchor rode, which should get wet—both to help it sink faster, and also to cool and lubricate fibers as the rode goes through load cycling.

If you want your ropes to stay a bit lighter in the rain and spray, waterproofing treatments can definitely help. In our testing, Nikwax Rope Proof made a 39-percent difference in water-weight gain after a dunking—compared to untreated line—after eight months of use. It also gave a subtle, but unmistakable, improvement in handling and reduction in snarling. It seems like good stuff to use on all sheets and halyards. We presume it would reduce halyard stretch in wet weather, but we did not test this (see “Practical Sailor’s Guide to Choosing Halyards,” for more on halyard stretch).

Treatments to Preserve Ropes and Lines through the Seasons
Nikwax Ropeproof provided multi-season protection. (Photo by Drew Frye)

We expect the treatment should last one or two seasons on halyards and less on sheets that spend time in the water, but re-treating sheets is easy. Cold-weather sailors will find big improvements, as treated halyards run free and sheets aren’t stuck to the deck. Nikwax also makes Polar Proof, a product specifically for synthetic insulating materials, which we’ve used for years on our winter gear, and seems to work just as well on ropes. We also tested a Granger’s 2-N-1 Cleaner (now called Wash + Repel), which did well, but not as well as Rope Proof.

Both Rope Proof and Granger’s 2-N-1 provided eight months of solid protection through winter spring and summer. Based on our experience, Rope Proof should give multi-season protection, while Granger’s will likely protect for only one season.

Not only was ice kept at bay. Squeaking on the drum was reduced, and lines tended to slip off the drum and run through blocks a bit more easily. Both waterproofing treatments eliminated squeaking on blocks for eight months. Our test boat was quieter than ever. Will this increase the durability of the line? We’re not going too far out on a limb, but reducing internal friction and wear certainly can’t hurt, and strains will be more evenly shared by all of the fibers.

Which waterproofing treatment is most economical, and which is most durable? Given the difference in treatment rates, no absolute conclusion can be drawn. To ensure real improvements in water absorption and freeze protection, we suggest using Rope Proof or Polar Proof at its recommended treatment rate; the product was developed and tested, and is specified for this application. We also suggest using the leftovers to treat additional lines. Although the treatments may be somewhat less effective, it makes the cost more economical, equating to only a few dollars per line.

Given the benefits of an almost 40-percent reduction in water weight gain, significant improvement in handling and running through blocks, and reduction in internal friction, rope squeaking, and wear, these treatments should be a standard part of cruisers’ line maintenance regimens, and they are a clear win for low-budget racers.

For the fastidious owner who wants the ultimate in clean, easy-handling docklines, factory dry-treated lines absorb less water, making for more comfortable docking in cold weather.

For our complete report on treating ropes for protection against the elements, see “Aftermarket Cordage Treatments.” For more on preparing your boat for winter sailing, search “winter sailing” in the search box. The following three articles, loaded with links to winter-relevant reports, are a good start:
Floating Through the Winter Season
Winter Sailing Tips for Diehards
Sailing Clothes for Cold Climates

Darrell Nicholson
Practical Sailor has been independently testing and reporting on sailboats and sailing gear for more than 50 years. Supported entirely by subscribers, Practical Sailor accepts no advertising. Its independent tests are carried out by experienced sailors and marine industry professionals dedicated to providing objective evaluation and reporting about boats, gear, and the skills required to cross oceans. Practical Sailor is edited by Darrell Nicholson, a long-time liveaboard sailor and trans-Pacific cruiser who has been director of Belvoir Media Group's marine division since 2005. He holds a U.S. Coast Guard 100-ton Master license, has logged tens of thousands of miles in three oceans, and has skippered everything from pilot boats to day charter cats. His weekly blog Inside Practical Sailor offers an inside look at current research and gear tests at Practical Sailor, while his award-winning column,"Rhumb Lines," tracks boating trends and reflects upon the sailing life. He sails a Sparkman & Stephens-designed Yankee 30 out of St. Petersburg, Florida. You can reach him at


  1. A quandary. Waterproofing usually requires using PFAS. Nikwax says it doesn’t use any but their website doesn’t state what it does use. Is the chemicals used just a close cousin to these chemicals or a revolutionary new waterproofing strategy that is environmentally friendly?
    Before I contribute to possible environmental degradation I try to consider the consequences as well and do a cost benefit analysis.

  2. Also, when you tested Rope Proof, did you experience a really nasty, toxic odor from it such as described in this review: “I bought this to try to prevent the sheath of an old climbing rope from further disintegration. I didn’t really know what I was getting into with this. The chemical smells so toxic! And this becomes a meticulous process since your life depends on your climbing rope. But regardless the directions say that you need to agitate for 2hours! Then you dump all the chemical down the drain and throw the rope in the washing machine to wash the extra off. This smells terrible in the house and cannot possibly be ok to breathe! It cant possibly be environmentally safe – I wore gloves I was so afraid to touch it. It made me very dizzy. There are so many deals to be had on climbing ropes that this is just not worth the health risk and effort. For the cost of this product, a double dry climbing rope could easily be had over a non-dry rope.”

  3. Water proofing sprays contain PFAS “forever” chemicals which are toxic and simply continue to accumulate in the environment, in animals and within us. They are not scrubbed out of wastewater treatment and a very sure way to damage the ocean environment “forever” is to spray ropes with this stuff out on your multihull netting as is being done in the photo. Nikwax is therefore banned in the US for a very good reason. There are over 600 different types of PFAS chemicals becuase they have such fantastic properties for an immense variety of uses, from pizza boxes to firefighting foam. If we’re worried about nuclear waste we should be very worried about PFAS. I won’t suggest any links. Check it out yourselves

  4. The meat of the article was written some time ago and was just re-published as a seasonal item. Yes, some things have changed.

    Rope Proof was discontinued, but Polar Proof is very similar, and we use it on ropes with good success.

    Polar Proof is PFAS-free. NikWax is not banned in the USA. In fact, if I recall correctly, Nikwax is known for being one of the few companies that never used PFAS.