July 2008 Issue
Also with this article...
Lines, Snubbers, and Other Gear for Battening Down Ahead of Storms
Can the right gear increase your odds of surviving extreme weather?
No one need lecture most sailboat owners about the profound dangers of hurricanes and tropical storms. That goes double for those whose boats are berthed in the Gulf states or along the Atlantic Coast. Much of this awareness is due to recent hurricane seasons that have been exceptionally devastating.
The 2004 Atlantic hurricane season was one of the deadliest and most costly on record. Some 3,132 deaths and roughly $50 billion in damage were attributed to these storms. In particular, the four hurricanes that made landfall in Florida—Charley, Frances, Ivan, and Jeanne—caused tremendous damage. In just that one U.S. state, 133 people died and property damage was estimated at $22 billion for the 2004 season. In Haiti, Hurricane Jeanne, alone, resulted in over 3,000 deaths, according to the National Hurricane Center.
For sailboat owners, the storms in 2005 meant bleak news as well. BoatU.S., the boatowners’ advocacy organization, calculated losses that year approaching $1 billion (including boats, marinas, and boating clubs).
All of this is pertinent because the outlook for the 2008 hurricane season is no better. According to noted researcher William Gray of Colorado State University, the Atlantic will see 15 named storms over the coming months, with a better-than-average chance that at least one major hurricane will hit the U.S.
Damage in severe storms is nearly unavoidable. Securely moored vessels are frequently harmed by those less securely moored that break loose and by skyrocketing debris. Storm surge wreaks havoc on even the best prepared boats. But it is possible to minimize the destructive forces of a hurricane through prudent planning, proper techniques, and appropriate equipment. Regarding the latter, Practical Sailor has been carefully observing an ever-burgeoning crop of products devised expressly for berthing, mooring, or storing boats in storm-prone regions. Keep in mind, this article is not a guide for how to secure your boat in a storm. This report is primarily an overview of the products—some tested, some not—that are aimed at securing a boat in the water for a storm. Before getting into the gear, however, it’s worth discussing the options.
Make a Plan
Uncrowded marinas well inland may offer safety, but those vulnerable to storm surge are a poor choice of refuge. Insurance data indicates that hauling the boat and securing it ashore increases the odds of survival, but you need only look at what Hurricane Ivan wrought in Grenada in 2004 to know boatyards present their own risks. If hauling, ensure that your boat is securely tied down and supported with multiple jackstands. Ideally, the yard should be well inland, roomy, and well managed. Tightly packed boats and hasty haulouts can lead to shortcuts (like leaving furling gear on) that put your boat and neighbors at risk. Unstepping the mast and tying it down helps lessen the risk of wind damage. Yards vulnerable to storm surge should be avoided, if possible.
Bob Adriance, the technical director at BoatU.S., says: "If a marina gets hit by a hurricane, it’s very difficult to minimize the damage if a boat is in the water." Several owners of boats in Southwest Florida survived the equally devastating 2005 storm season by moving upriver and using homemade hurricane moorings in an isolated spot.
The reality is that in most localities, the majority of sailboats will remain in the water—docked or moored—during hurricanes. If a marina or dock is your only option, see if it is possible to move into a larger slip prior to the storm’s onset. Securing boats to more distant pilings and cleats means that they will have greater latitude to move and can rise and fall with the surge more safely. Adriance and his colleagues also advise using much larger-diameter lines for docking in these situations, and they recommend using long lines tied to secure fixtures well away from the boat to accommodate storm surge. Centering the boat in a canal is one tactic that many sailors used to survive the Florida blows.
Whether you’ll be keeping your boat at the dock, on shore, or moored elsewhere, it’s imperative that you eliminate windage by removing sails, biminis, dodgers, and other on-deck accessories (barbeque grills, radar radomes, etc.). Adriance also recommends unstepping your mast if at all practical. This, he says, is critical for boats kept on shore.
Simple common sense tells you that increasing the number of dock lines means decreasing the chances that a boat will break loose. In the case of Hurricane Fran in 1996, a BoatU.S. catastrophe team that visited the landfall site in North Carolina estimated that as many as 50 percent of the boats damaged could have been saved by using more and better dock lines. The team collectively specified the need for lines that were longer, larger, arranged more sensibly, and better protected against chafe. This information appears in BoatU.S.’s publication "The Boater’s Guide to Preparing Boats & Marinas for Hurricanes," a useful, 12-page booklet available at www.boatus.com. What you won’t find there is exactly what kind of line to use.
Practical Sailor investigated nylon line recently. (See "Nylon Rope Endurance Test," December 2007.) After breaking several used docklines (some as old as 12 years), testers found that some of the lines broke at one-third their ratings when new. This is due to UV degradation as well as the wear and tear of load cycling. Testers also determined that larger-diameter lines are definitely better. They have more mass to withstand chafe longer, and surging waters can move a boat so violently that dock lines stretched over a chock or rail will create sufficient heat to begin melting the fibers internally. The larger the line, the less stretch and the less chance of internal melting.
In that December article, line experts at New England Ropes recommended three-strand nylon line for its elasticity (to absorb dynamic loading), toughness, and the ability to withstand physical abuse. Other studies have suggested joining nylon and polyester line in the same tether. Their argument: Nylon absorbs dynamic loading better, but polyester line (like Dacron) has shown better abrasion resistance and is less liable to heat-related failure.
The authors of one study conducted by the Massachusetts Institute of Technology on line chafe suggest connecting nylon and polyester ropes via eye splices in each, with the polyester portion leading through a chock or over the rail to the connecting splice. Anyone taking this approach should factor in roughly a 10-percent drop in line strength due to that splice. (Knots diminish line strength even more. Practical Sailor tests indicate that bowlines reduce line strength at the knot by about 30 percent.)
With due care to splices, chafe gear, and unions, adding a polyester tether to cope with inevitable chafe points is viable. In Practical Sailor’s view, however, conservatively sized, new—or lightly used—high-quality, three-strand nylon line and superior chafing gear are a suitable, cost-effective, and practical means of securing to fixed points ashore during a storm. To reduce elasticity or increase chafe protection, increase line size.
Although three-strand nylon line has excellent elasticity, it is likely that a snubbing device to absorb shock loading will lengthen the line’s lifespan. There are numerous products on the market that have been developed to do that: Shockles (Practical Sailor March 1, 2004) and Bungy Schock Absorbers (Practical Sailor July 1, 2004) are among those products. (Tommie Springer snubbers, an Australian product reviewed in the June 2006 issue, seems to be off the market.)
These products are generally designed to absorb some of the line strain in normal docking and anchoring conditions, and although we have load tested a few of them to their useful maximum, we have not used them in actual storm conditions. While some of the more rugged units should help reduce chafe and heat build-up in the early parts of a storm, they would likely break or stretch beyond their useful limit in a storm. Again, any knots or splices will weaken a system.
A relatively new entry into the field are lines with integrated snubbers, such as those sold by Synergy Marine. Synergy offers braided polyester dock lines from half-inch to 1-inch diameters. The shock absorber is simply a section of bungee cord that is inserted during the braiding process. Practical Sailor has yet to test this product.
Ultimately, the best storm strategy regarding dock lines is to make sure you keep new lines on hand for heavy-weather applications. Go with the largest diameter that your boat’s cleats or deck fittings will accommodate, maximize chafe protection, and double up on each line.
In extreme weather, reliable chafe gear is an absolute necessity. Though it won’t ensure that your dock lines or mooring pendants won’t fail, it will at least postpone that failure. But not every form of chafe protection will work. Recent tests have determined that PVC hose can actually accelerate the demise of three-strand nylon line (Practical Sailor December 2007).
Practical Sailor last conducted a full-fledged test of chafe gear in 2011. At the time, we examined products made from solid hose, woven fabric, leather, tape, and our own concoction made of towels. In the resulting article, we deemed Fjord Chafe-Pro the top product due to its greater longevity versus our chafe machine. Our testers also had good results with other products. No product endured unscathed, and we cautioned readers to monitor chafe gear if possible.
Additionally, there are several other products on the market that seem worth a look. Any product you choose--homemade or store bought--should meet some or all of our criteria for good chafe gear: good abrasion resistance, easy to install and keep in place, promote the dissipation of heat, and allow water to reach the line and cool it.
Tidal and Surge Aids
There are a number of products on the market that advertise themselves as aids for docking in regions where tidal waters rise and fall significantly. Practical Sailor has tested one—Tideminders (Practical Sailor June 2006). Aids like these enable dock lines to either travel up and down a piling or otherwise accommodate the rise and fall of the vessel in some fashion. In an extreme storm, precautions need to be made to keep them from riding right over the top of a piling.
Aside from Tideminders, Practical Sailor has yet to test these products, so—again—we can’t offer endorsements. However, in situations where there is little room for lateral movement, a system that allows dock lines to rise and fall with the water should perform better than no system at all. The products that have come to our attention break down into two basic categories: permanent applications that mount to pilings and more simple line protectors that float the dock lines (i.e. Tideminders).
Hurricane Hoops are similar to Tideminders. Where the latter are simple, high-density polyethylene spheres with a hole molded into them to accept the dock line, Hurricane Hoops are made of a similar plastic, but the individual "pearls" are elliptical in shape and come strung together by way of a wire pendant. Both products will float a dock line and protect it from wear and tear on pilings.
The two permanent products that Practical Sailor is aware of are the TideSlide and the Slide-Moor, which each use metal tracks or poles that mount to a piling. Each system has a cleat that moves up and down along the track or pole, carrying the dock line with it. Whereas the simple products are fairly economical (roughly $50/piling), these permanent products are expensive. For boats up to 50 feet, the TideSlide can run from $649 to $1,100 for one piling.
Tideminders, because they have been enduring a Practical Sailor test for more than a year, are recommended. As for the other products, a test is currently being developed.
None of the products mentioned here is a substitute for advanced planning and a keen weather eye. If you decide to leave your boat in the water during a named storm, try to move it to protected water or at least to a large slip. Then, remove all windage and double up on your dock lines or mooring pendants, ideally with brand new lines. Also, apply chafe protection to these lines generously because they’re certain to endure significant strain. If at all possible, use long lines tethered to pilings or fixtures that are at least as far away as the length of your boat. When tying to cleats, try to orient the line so that it’s parallel to the lengthwise axis of the cleat as it runs ashore or toward the boat. This enables the cleat to offer the greatest resistance. And whatever you do, avoid staying on board the boat during the storm.