The Weight of Myth
Misinformation and Kayaking
by Wes Kisting
Years ago, many factors motivated me to establish this website. One of the biggest was the wealth of myth and misinformation I had stumbled across (and naively believed) during my own introduction to the online kayaking community. Back then, there were few outstanding resources for kayaking information on the Internet. The majority of online articles were short, superficial, and dedicated to rehashing the same introductory basics. Meanwhile, the best information was buried somewhere deep in old posts on small kayak discussion forums. For every hour I spent paddling, I spent five or ten hours surfing the Internet to find one more little tip that might help me improve my skills. Often, the advice I found was quite poor or thoroughly incomplete. So, when I finally reached a level of experience that allowed me to distinguish good advice from bad, I created this site to spare others the same effort and confusion.
A lot has changed since then. The general quality of kayaking websites and online articles is much better now, and I would like to think that this website (crude as it began) contributed to that trend. Yet one significant problem continues to plague many of the best online kayaking resources. It has taken me a long time to put the problem into words. In fact, I'm still hard-pressed to give it a precise name, so you'll have to settled for a descriptive phrase. I call it: "the ongoing circulation of myth and misinformation which is cloaked in the intimidating disguise of authoritative 'fact,' and perpetuated by paddlers who are guided more by enthusiasm or ego, than by carefully reasoned considerations."
Quite a mouthful, isn't it? I tried to find a shorter name, but it needed to capture the immense complexity of the issue. Besides, however hard it is to name the problem, it's even harder to grasp how much confusion, stress, and general havoc it can wreak among unsuspecting or inexperienced kayaking enthusiasts who browse the world-wide web for trustworthy advice. I'll provide a specific example of the problem at the end of this article, but first, let's consider what makes the problem so disturbing and potentially destructive.
The Nature of the Damage
There's really no way to gauge the amount of damage caused by myth and misinformation. Many paddlers purchase the wrong kayak, or wrong paddle, or wrong PFD because of it. Many paddlers suffer back problems, tendonitis, hypothermia, dietary deficiencies, or severe dehydration because of it. Some paddlers get lost or injured because of it. Some paddlers take profoundly unnecessary risks, or put other paddlers in real danger because of it. Would-be paddlers often fail to enjoy the sport because of it. And yes, I dare say (with all seriousness), that some paddlers probably die because of it. Regardless, many, many paddlers make poor decisions, maintain poor technique, or suffer undue psychological anxiety because of it.
What is the "it" exactly? Well, "myth and misinformation" is the general name I've given it, but that name doesn't quite do it justice. Perhaps I should have called it a plague, an infection, a virus. It certainly creeps like a disease into every imaginable facet of kayaking advice. It encompasses so many, many things: It's bad advice about how to size a kayak, or grip a paddle, or sit, or pack, or stretch, or diet, or read a map.... the list goes on and on and on. What makes it so dangerous is the way that this bad advice combines with partial truths and heated conviction, gathering credibility and "evidence" the longer it circulates. Perhaps it gains support from misperception or misplaced enthusiasm. Perhaps it gets "proven" with compelling "scientific" data or impressive charts and graphs. Perhaps it gets advertised by marketing savy retailers, or authors, or armchair experts who really don't know (or don't care) how their claims pan out in real world conditions. However it happens, sooner or later, what started as bad advice suddenly becomes "reliable, irrefutable fact." From then on, a few independent thinkers may dare to question it, but for the most part it spreads to the unsuspecting masses with undue authority.
I've seen paddlers spend a lot of money and time buying or building a kayak that they hated, all because some expert assured them it was "the best kayak ever designed." ("Best kayak for who, and for what use?" I would have asked.) I've seen paddlers trade a competent paddling style for one that actually causes them physical pain, simply because they were told that the more painful way was the "right" and "only" way to paddle. I've seen paddlers resign themselves to putting up with numb legs and a numb butt, simply because they were told that the laws of stability demanded that they modify (or in a few cases, not modify) their seat, even at the high cost of comfort. I've even seen amateur kayak builders (myself included) waste long, stressful months trying to understand and incorporate exceedingly sophisticated or intricate principles of hydrodynamics into their designs, only to later find that these same factors (once declared to be "of utmost importance") don't actually apply to the speeds, weights, sizes, or external forces which bear upon a kayak in the real world.
The Origins of Myth
Where does all this myth and misinformation come from? There are many sources, but I think there are four major culprits: (1) the influence of tradition; (2) the distorting lens of subjectivity; (3) the undue persuasiveness of scientific data; and (4) the "armchair expert" factor. Let's look at each tendency in greater detail.
The Influence of Tradition
Much myth and misinformation begins, innocently enough, with a simple set of mistaken assumptions or an honest misunderstanding about a particular set of issues. They may even start out as sincere questions, not rigorous assertions. Regardless, as they continue to circulate in articles, on forums, and sometimes even in books (print materials are subject to better quality control, but not immune to inaccuracies), they take on a life and authority of their own. Eventually, what started as error or speculation becomes a part of "conventional wisdom" in a way that discourages even extremely intelligent people from questioning their logic, their accuracy, or their origins. If it goes unchallenged long enough, it may even earn the status of "irrefutable fact." The influence of tradition is very strong. As the saying goes, "an old lie is easier to believe than a new truth." Once a mistaken "fact" has circulated for so long, it's hard to expose the error.
The Distorting Lens of Subjectivity
Although we might hope that the reviews, recommendations, and scientific "tests" we read online are accurate, the reality is that the vast majority of this information is inescapably subjective and, consequently, thoroughly skewed by all kinds of unquantifiable variables. Objective-seeming "side by side comparisons" of different kayak designs may appear to "prove" that one design is "faster," "more efficient," "more maneuverable," or "more stable" than another design, but often there is little to no consideration given to variables like paddler size, paddler weight, paddler experience level, paddling technique, the amount of cargo, the intended use, the variety of paddling conditions, the shape of the paddle, and many, many other factors which can affect (in some cases, dramatically) the feel and performance of a particular kayak. Often, there is even less said about the particular experience level of the person writing the review. Still worse, an alarming number of reviews on the Internet are posted by novice kayakers with little or no basis for making a useful assessment of the gear they are reviewing. Enthusiasm or disappointment often gets the better of many novices. Delighted with the purchase of their first kayak, some post reviews declaring their kayak to be the "best I've ever paddled" or "an excellent performer in all conditions" (or some other such hyperbole). Or, alternatively, a novice with unrealistic expectations about kayaking may find the sport too slow, too wet, and too laborious. Annoyed and angry, he may vent his frustrations by posting a damning report about the poor performance of his kayak. Unfortunately, none of these extenuating circumstances may get mentioned in the reviews they post. Even worse, kayaking novices acquire the vocabulary of an experienced reviewer much faster than they acquire the actual experience needed to make a fair evaluation. They sound authoritative, but they are not.
On the other hand, very experienced kayakers are also subject to this phenomenon. During a long expedition down the Mississippi river, a friend of mine spent several loud hours lamenting the thousand deficiencies of his self-designed, self-built kayak. Over the course of 12 days and 420 miles of paddling, I can't remember him voicing a single positive comment about his craft. (In fact, the tiresome torrent of complaints was a big reason I ended the trip when I did, even though he continued on.) Later, however, I discovered that he had posted free plans for the same kayak online, with no hint of warning about the endless problems he had railed against on the Mississippi. Instead, he offered a very brief description of the design which might even qualify as "reserved praise." Whatever the reason for this discrepancy, I am confident that if he had written a description of his kayak right after our Mississippi trip, it would have read very, very differently than it does now. During our trip, he vowed to "sell or burn" his kayak the moment he got home, yet his website reports: "Overall, I'm happy with this kayak. I'm glad I built it" (Jan. 4, 2006). Which assessment is accurate? Perhaps both. Regardless, the point is clear: Subjective experience (the context of the moment) can dramatically sculpt or distort a person's perception of truth.
The Undue Persuasiveness of Scientific Data
I teach college-level rhetorical analysis for a living. One of the first things I teach to my students is how logos (appeals to logic) and pathos (appeals to emotions) are often used to manipulate people into trusting or believing what someone says. Manipulative appeals to our emotions tend to be more powerful, but they are also easier to detect. Manipulative appeals to logic, on the other hand, can be very sophisticated and very difficult to guard against. This is because of what I call the "undue persuasiveness of scientific data." It's a fact of life that most people are relatively lazy and relatively trusting. If you support any reasonable-sounding argument with enough "facts," "data," and "statistics," very few people will bother to check the accuracy of your facts or question the logic behind your claims. For this reason, a lot of myth and misinformation goes unchecked simply because it is accompanied by numbers, charts, and graphs which allegedly "prove" the truth of their claims. But even when the numbers, charts, and graphs convey some real shred of truth, they don't always prove what they claim to prove. If I told you that 90% of people with a receding hairline also wake up to pee at least twice during the night, it doesn't necessarily prove that there is any connection between receding hairlines and frequent urination. Even so, if I tossed in just a few more cleverly arranged facts and statistics, I bet you would find yourself checking your hairline in the mirror the next time you happen to drink too much water before bedtime. Now imagine how much more persuasive I could sound if I picked a more sophisticated and more reasonable-sounding (but still false) argument to support with statistics and data. That's the power of numbers. They sound like facts (even when they aren't) so most people trust them.
The Armchair Expert Factor
One last major contributor to myth and misinformation is the "armchair expert." An armchair expert is the sort of person who spends great amounts of time thinking about and researching a particular topic (often an obscure one, but not always). In many cases, these armchair experts devise strange ways to "test" a specific hypothesis or prove a particular conclusion. Whatever their methods, most of the armchair experts you find on the Internet are people who enjoy sharing their findings and reporting their information at length. This is where the trouble, if any, begins. Many armchair experts are admirable, responsible thinkers. They make a serious effort to be objective and to properly contextualize their opinions. Often, they produce extremely valuable information. But for every good egghead, there are at least two or three bad ones. The problem with "bad" armchair experts is not that they lack intelligence or good intentions; it's that they lack a proper sense of responsibility for the information they report as "fact." Bad armchair experts tend to collect accurate data and information, but then misapply this information (unintentionally, in most cases) in a very different context to "prove" a very persuasive-looking, but ultimately wrong, conclusion. What makes their findings particularly dangerous is that (1) they often go to great lengths to publicize their opinions online (replete with supporting data, however erroneous) and (2) this data looks persuasive thanks to the "undue persuasiveness of scientific data" which I described above.
Escaping the Cycle
There are other, subtler factors that feed the cycle of myth and misinformation I've been describing. Nonetheless, the important thing is that you remember the oft-forgotten maxim: Don't believe everything you read. Most of us know better than to believe everything we read, but plenty of us (myself included) are lazier or more trustful than we should be when it comes to checking the facts. If we want to escape the cycle of myth and misinformation, we all need to have a better respect for the manipulative power of rhetoric. We should check our facts, ask plenty of questions, demand clarification, and make no pretense of certainty in matters of sheer speculation. More importantly, we should be careful not to perpetuate myth and misinformation ourselves. Don't assert the truth of some "fact" unless you're certain you know what you're talking about, and you really have the experience to back it up. I'm not saying we can't talk about things we don't have a college degree in. I'm saying that if we do talk about things outside our personal expertise, we ought to admit that we're on unfamiliar ground, rather than speak as if we were an authority on the issue. We should qualify our language, tell people when we're making assumptions, and be more honest with ourselves about what we do and do not know "for sure." To their credit, a lot of people on the Internet already do this. But for every responsible person who qualifies their arguments, there are at least a dozen more (perhaps hundreds more) who are more concerned with their ability to profit (in dollars, in web traffic, or in ego) from sounding like an expert. Beware those folks, and do your best to expose (fairly and politely) the errors they perpetuate.
A Current Example of the Problem
This editorial was originally planned to end here, but recently I stumbled across an excellent, specific illustration of the problem in an impressively sophisticated form. I think it reveals (extremely well) how hard it is even for highly intelligent people to detect myth and misinformation when they see it, or to prevent themselves from repeating it as "fact" to others. I'll share that example with you now to demonstrate the scope and magnitude of the problem. Be warned, however, that it's a long and somewhat jargon-intensive story. I promise to do my best to make it worth your time.
[Editor's Note: The ensuing discussion of weight and performance has been re-printed in more concise form under the title Weight, Drag, and Performance. The original article is retained below to illustrate the problem of myth and misinformation, but readers who are interested in the topic of weight are encouraged to read the revised version for a more concise account.]
Awhile ago, I received an e-mail inquiry about my solar-powered battery pack and electric bilge pump system. The author of the e-mail mentioned that he had inquired about my system on the Guillemot Kayak Forum, an oustanding online resource for kayak builders. Curious, I visited the Kayak Forum to see what others were saying. To my surprise, one forum member objected to my system on the grounds that its weight (apparently heavy by his standards) would inescapably reduce the kayak's performance by increasing drag, reducing efficiency, requiring greater effort from the paddler, and slowing overall progress. I clarified that the design was only intended to support extended rough-water expeditions, in which case a self-recharging battery system (able to maintain batteries and electronic equipment) and hands-free bilge pump (able to facilitate a faster, safer recovery after a capsize) was well worth its weight.
Oblivious to the subjective assumptions underlying his own position, the forum member stubbornly insisted that the weight trade-off was unacceptable. After citing several impressive-looking calculations about weight and drag (carried to the fourth decimal place) and producing an appropriately scientific-looking graph, he concluded (in the authoritative rhetoric of an expert): "The loss in efficiency that occurs [with added weight] should dictate that the lightest system available be used on long distance trips."
At one time, I might have been swayed by the scientific tone of his rhetoric. I might even have applauded his effort to substantiate his claims with data. But wise to the ways of online forums and wiser in the ways of kayaks, I knew better. His supreme confidence in numbers and graphs reinforced my suspicion that his response was informed more by theoretical calculations than practical experience. Moreover, a self-serving recommendation of his own article "The Lightweight Secret" (the topic of the thread was "solar power and electric bilge pumps", not "weight, drag, and performance") made it clear that his motive was to fish for web traffic, not to help the person who had inquired about my system (and who had expressed no concerns regarding its weight).
Confronting the Cycle of Myth
Whatever the motive, the respondent's claims about weight (both in his post and in his self-recommended article) were grossly oversimplified and in many cases, demonstrably false. It was clear that his understanding of the concepts he cited for supporting "evidence" had been shaped almost entirely by the fancy data which can be gleaned from freeware kayak design programs like KayakFoundary, Hulls, KAPER, or FREE!ship. (His article, in fact, cites KAPER and FREE!ship explicitly as sources.) Though sophisticated and immensely useful to budding kayak designers, these programs encourage one disastrous side-effect: They are so chock full of delicious numbers and exquisite data, and so easily available without any requisite education in the sophisticated concepts they reflect, that they sometimes encourage egotism and self-delusion. Swayed by the power of the numbers at their fingertips, some users suddenly pronounce themselves experts on topics as complex and mentally taxing as NACA profiles, hydrodynamics, propulsion, efficiency, and surface friction. At least, that appeared to be the case with this particular author, who not only showed a poor grasp of what those numbers and data actually reflected (or were capable of reflecting, for that matter), but proceeded to write a tantalizing article about the subject called "The Lightweight Secret"a title which suggests some kind of special, inside knowledge on his part. The problem is that this alleged "secret" is based on a series of profound misconceptions persuasively strung together as a very scientific-sounding argument.
As the holder of a research-based doctoral degree, I feel an especially strong ethical responsibility for the knowledge I choose to report or defend as "truth" or "fact." Yet here was an inexperienced kayaker and even more inexperienced designer, boldly proclaiming the universally detrimental effect of weight, based solely on a remedial assumption that since weight causes friction, and friction slows the boat, the paddler of a heavier boat must arrive at his destination later and more fatigued. It sounds true, perhaps, and in the case of many watercraft, it is true (though not without qualification). But in context of the real-world circumstances of kayaking, the argument doesn't hold waterat least not in the absolute terms he invokes. Nonetheless, a visit to his website confirmed that he had written an elaborate article to "prove" the veracity of this myth. To see how the myth operates, let's examine his claims more closely.
Debunking the "Secret" of Weight
After discussing how friction reduces efficiency in a kayak, and correctly observing that an increase in the weight of a kayak increases friction ("drag"), the author of "The Lightweight Secret" erroneously concludes that a lighter kayak is necessarily faster and more efficient during an expedition. That's right, I said "erroneously concludes." But where is the error? If friction reduces efficiency (true) and adding weight to the kayak increases friction (also true), doesn't that mean that adding weight must reduce overall efficiency and slow overall progress? In a word: No. At least not in the context of expedition travel which the author claims to be addressing. It certainly sounds logical; but it rarely works out that way in the real world. Nonetheless, the author of "The Lightweight Secret" portrays this myth as a scientifically proven fact. Before I show where his logic breaks down, let's examine the data, persuasive rhetoric, and confident tone with which he advances his claims:
Those are some exciting and impressive claims, but unfortunately, despite the data and graphs the author cites as "evidence," a lighter kayak will not usually produce the "real world tangible positive results" he promises. Why not? Because the author is making a subtle, but immensely problematic assumption about the relationship between friction, efficiency, and weight. His numbers may be right, but his reasoning fails to consider a lot of important factors. Let's try to separate fact from fiction.
The Partial Truth
First of all, the author of "The Lightweight Secret" is right about a few things. The numbers he reports probably do accurately reflect changes to the factors they were intended to address (though they don't support the conclusion he uses them to prove). Friction does reduce efficiency. Weight does increase friction (i.e., "drag") on the kayak. And, all other things being equal, a kayak which experiences greater drag will paddle slower and less efficiently than a kayak which experiences less drag. Let's stop there: All other things being equal is the operative phrase. Data concerning the friction and drag of a kayak may be useful when, say, comparing two different kayak designs to decide which should be faster and more efficient (assuming all other factors, including weight, remain equal). Under identical conditions, the kayak with the lower coefficient of friction or predicted drag will almost certainly be faster and more efficient. That's why kayak designers try to minimize drag in their designs. In this hypothetical context (and only in this context) the author's claims about increased efficiency and reduced paddling time appear theoretically true. If you design a kayak with less drag, it should technically paddle "faster" and "more efficiently" than the same design would if it had more drag. Yet even this claim, reasonable as it appears, deserves qualification because "faster" is a relative term which must not be divorced from context. To note just one possible exception: A kayak that is "faster" and "more efficient" but has difficulty paddling in a straight line may take significantly longer (and require more effort) to get to its destination than would be the case in a "slower, less efficient" kayak that tracks straighter.
There is another problem with the term "faster." A kayak that is subject to less drag than another design may be "faster" in the sense of being able to achieve a higher theoretical maximum speed, but the physical effort required to actually exploit this higher speed potential often lies well beyond the strength or comfort level of most paddlers. It's far more useful to measure the comfortable "cruising" pace of a kayak, in which case the speed "advantage" of a "faster" kayak (assuming a fair comparison between two kayaks of similar proportions) is often as little as 0.2 knots or less (assuming the same amount of effort is applied to paddle each kayak). Moreover, the vast majority of reputable kayak designs (not poorly-designed "free kayak plans") are capable of reaching and sustaining very nearly the same comfortable cruising pace. If we imagine a typical 16 to 18-foot sea kayak with a 22-inch beam, this comfortable cruising pace is usually somewhere between 3.5 and 4.5 knots. (Of course, what counts as "comfortable" is also influenced by important variables like paddler technique and paddle design). Any speed advantage which a particular design appears to offer beyond this practical range is irrelevant (realistically speaking) because the exponential increase in water surface friction at higher speeds makes it virtually impossible to sustain a higher speed for long.
What really separates one design from the next is the fact that a particularly well-designed kayak may be able to sustain an average, comfortable cruising speed with less effort on the part of the paddler. In a simple stroke-to-stroke comparison the difference in effort will feel extremely small (often virtually undetectable), but over the course of a whole day of paddling, even a slight reduction in effort can add up to a profound difference in fatigue. Consequently, it is primarily (though not entirely) in terms of paddler endurance or fatigue that differences in efficiency promise to produce "real world tangible positive results." That is why a paddler choosing between two similar kayaks might want to choose the mathematically "faster," "more efficient" design (with a lower predicted drag). Even so, as shown by the example in the previous paragraph, the math still cannot guarantee a more positive real-world experience. Even more importantly, no matter what "The Lightweight Secret" alleges, the conclusion does not logically follow that we can unfailingly exploit the benefits of reduced friction by reducing the weight of a kayak. Let's see how the logic goes awry.
The Rest of the Story about Weight
When we add more weight to a kayak, we can safely assume the additional weight does (as the author claims) generate additional friction and drag. We can even assume (relatively safely) that the added weight will reduce the theoretical maximum speed and actual efficiency of the kayak. Surprisingly, however, we cannot assume that these effects will result in slower progress during an expedition. In fact, the opposite often proves true. A heavier kayak often paddles significantly better on an expedition than a lighter kayak, getting you to your destination sooner, with less fatigue. In all my years of kayaking (regardless of which kayak I've paddled), adding 20 to 40 pounds of expedition gear to my hull has consistently improved my actual progress toward my destination by at least 0.25 knots per hour, reducing my time on the water (over the course of several days) by several hours!
Yes, it technically takes more effort to accelerate a heavier kayak up to speed. Yes, it technically requires more effort to keep the kayak moving at that speed. Yes, the kayak is technically less efficient when it's loaded with gear. In fact, if we measure "actual speed" and "actual effort" at any isolated moment in time, I am confident we will always find that the heavier kayak is technically moving "slower" and requiring "more effort" per stroke. How, then, do I explain the consistent improvement to my progress during expeditions? How can this data possibly be true? Well, it's because of several subtle, but significant extenuating factors which influence an expedition, but which programs like KAPER and FREE!ship are not designed to address. (They're design and drag programs, not propulsion simulators.) The first two factors are interrelated: (1) the nature of kayak propulsion, and (2) the role of momentum. Let's consider how these factors fit into the performance equation which "The Lightweight Secret" distorts.
Propulsion and Momentum: The Virtues of Weight
If we were talking about a boat with a constant source of propulsion (a motor or a sail, for example), and ignoring variables like directional stability (how well the boat maintains a straight course under different loads), we could safely assume that our boat would always travel slower when we add weight to it. Why? Because, as the author of "The Lightweight Secret" rightly asserts, the extra weight produces extra drag, the extra drag requires more effort to keep in motion, and the loss in effort causes a reduction to actual speed. But kayaks are different.
For one thing, they are propelled by a human paddler, not by a motor or sail. A paddler is only an intermittent source of propulsion. When the paddle is moving through the water, it is propelling (accelerating) the kayak just like a motor or sail would do, but between strokes, in that brief moment when one paddle blade is exiting the water and the opposite blade is preparing to enter it, the kayak is no longer being propelled. In fact, the kayak is slowing down (however unnoticeably) because its propulsion has stopped while the surface friction of the water is still hard at work. To exaggerate the image, think of a kayak like a fishing boat with an unreliable motor that keeps racing, then sputtering, racing, then sputtering. The source of propulsion is intermittent; it starts and stops, rather than remaining constant. Even an extremely well-tuned paddling technique (which virtually eliminates the lag time between strokes) is subject to this fact.
For the sake of discussion, then, let's say that the paddler is constantly cycling back and forth between two distinct phases: the "propelling phase" (the time the paddle blades are actually moving through the water, propelling the kayak) and the "halting phase" (the time between strokes, when the kayak is slowing down). Why does this matter? Because it has a direct bearing on how we understand the role of weight. Although extra weight may offer a consistent disadvantage to a watercraft with a constant source of propulsion, it can actually become a partial advantage for an intermittently propelled craft like a kayak. The secret has to do with momentum. When we say that it takes more effort to accelerate a heavier kayak than it does to accelerate a lighter one, we are talking about inertia: the amount of effort required to put a static (unmoving) load into motion. The heavier the load, the greater its inertia (i.e., resistance to being moved) and subsequently, the more effort it takes to put it into motion. During the "propelling phase" of a paddler's stroke, you must exert greater effort to keep a heavier load in motion. In this regard, it takes "more effort" to propel a heavier kayak. But the story changes dramatically during the "halting phase" of the same paddle stroke. During the "halting phase," the kayak is slowing down because (as I said above) it has momentarily lost its propulsion while friction is still hard at work. At this point, weight can offer an advantage thanks to the power of momentum.
Momentum is the opposite of inertia. It's the stored up kinetic energy which tries to keep an object in motion even after it is no longer being propelled. Imagine throwing a heavy bowling ball, but not letting go of the finger holes. What happens? You guessed it: You go tumbling down the bowling lane or get your arm jerked out of its socket! That's momentum! Heavier objects have greater momentum and consequently, a much greater ability to overcome friction. For this reason, a heavier kayak tends to glide further (or slow less) during the "halting phase" of a paddler's stroke. (It also tends to glide straighter.) This is a crucial point because it makes all the difference in the world to how we understand the effects of friction or drag in relation to weight. It proves that the "extra effort" you expend to put the kayak into motion during the "propelling phase" is not necessarily "wasted"; instead, it's stored and released in the form of greater momentum during the "halting phase" of your stroke. Although you expend more effort to propel a heavier load, some of that effort is gained back between strokes when the weight may actually help to keep the kayak moving. It's a small difference, perhaps, but the advantage often increases once you inject typical real-world variables like wind or wave action, which generally do less to slow a heavier kayak (thanks to higher momentum) than they do to slow a lighter one.
The problem with extrapolating data from programs like Hulls, FREE!ship, KAPER, etc. is that however accurately their data addresses the variables they were designed for, the numbers tell us comparatively little (virtually nothing, in fact) about how changes to the weight of any particular kayak will affect its actual performance. Yes, adding weight to any kayak will increase its wetted surface area and generate more drag, but once we consider the unique nature of kayak propulsion (an intermittent propulsion which repeatedly converts the weight from advantage, to disadvantage, and back again), we realize that this is not the whole picture. The fractional increase in drag which the author of "The Lightweight Secret" uses to support his thesis that "more weight equals a slower, less efficient boat" is only technically true. It ignores the many, many other factors which feed into the performance equation and which, in the real world, effectively disprove the claim that a lighter boat will always get you to your destination "faster," with "less effort." True, the heavier boat may cruise a bit slower or require a bit more effort to paddle, but it also maintains a more constant speed, with less fluctuation between strokes. It's like the old fairy tale about the race between the tortoise and the hare. The overconfident hare keeps stopping, while the tortoise chugs steadily along to win. What was the moral again? Oh yes: "Slow and steady wins the race." In this case, the hare (the lighter kayak) is only slightly faster than the tortoise (the heavier kayak), and the tortoise loses less effort to slowing down and reaccelerating. Already, then, the performance gap between them is beginning to close thanks to the realities of intermittent propulsion and momentum. Let's look at just a couple more factors to see why the tortoise very often wins over the long run.
Tracking and Lateral Resistance: The Friction Advantage
Another problem with "The Lightweight Secret" is the author's assumption that friction is always undesirable or detrimental to performance. Again, it sounds like a fair assumption, but think about it: Friction does a lot more than slow you down. It also makes it possible to accelerate (friction provides the resistance against the paddle blades to propel you forward). It also makes it possible to maneuver (friction as you drag your paddle blade or lean your hull to "carve" a tight turn). And perhaps most importantly, it makes it possible to paddle in a straight direction (lateral friction converts your off-centered paddling strokes into straight-forward energy). This last kind of frictionthe kind that helps you go straightis what determines a kayak's "tracking ability."
Tracking is extremely important, especially during a long-distance expedition. The better that a kayak "tracks," the straighter it travels, and consequently, the sooner it arrives at its destination. (Remember, the shortest distance between two points is a straight line.) How well a kayak tracks is largely governed by the length of its waterline. A longer waterline generates greater lateral friction (sideways pressure to keep the kayak from turning or slipping off course), which in turn yields better tracking performance and converts more of the energy in your stroke into straight-forward motion. If lateral friction didn't exist, a paddler's stroke would simply spin the kayak on its own center like a top. Why am I telling you all this? Because it feeds right back into our discussion of how weight can prove advantageous to performance.
When you add weight to a kayak, the kayak settles increasingly deeper into the water. Lateral friction increases and its waterline grows (how much it grows depends on variables like the amount of taper at the bow and stern, the volume of the kayak, the amount of weight added, and so on). This, in turn, improves tracking. Sometimes the difference is slight, but often it can be quite remarkable. As I said, it depends on many, many variables. Nonetheless, it is generally true that the tracking ability of virtually any kayak will improve (to greater or lesser extent) when it is loaded with 20, 30, or 40 extra pounds of gear (perhaps even more in the case of a "high volume" kayak). This is assuming, of course, that you do not load the kayak beyond its maximum design capacity, in which case performance might suffer severely.
Now consider the reality that the vast majority of commercially-available touring kayaks (and, in fact, a good number of the kits and plans available to home kayak builders) are designed to accommodate significantly more weight than that of a typical 6-foot-tall, 170-pound male or (even more dramatically) 5-foot-tall, 125-pound female. Because of this fact, very few paddlers will achieve maximum tracking performance in an empty (unloaded) kayak. Their body weight alone is simply not sufficient to sink the kayak down to its optimal "design water line" (DWL). In fact, I know two smaller-framed paddlers (both female) who have to load their low-volume kayaks with gallon-jugs of water to offset weathercocking on windy days. The difference the added weight makes is quite noticeable even to an external observer! Admittedly, in some cases, problems like these are caused by poor buying decisions (the person buys a kayak that simply doesn't "fit"), but in others, they stem from the reality that commercially available kayaks are designed to appeal to a broad audience (which generally means they won't be tailored toward smaller paddlers) or to carry a certain amount of cargo. The result is that their optimal capacity can be well above that afforded by body weight alone.
Why am I telling you this? Because it constitutes a strong rebuttal to the ridiculously simplistic argument that adding weight to a kayak always degrades its performance or slows its progress. It shows that, in many cases, adding weight to a kayak can improve its long-distance performance by positively affecting other factors which are particularly beneficial during a long-distance trip. (In some extreme cases, like the weathercocking example of the two women above, adding weight may even improve short-distance performance.) Certainly, a lighter kayak will technically be "faster" and require "less effort" to paddle. Certainly, in a short sprint race, a lighter kayak will win almost every time over a heavier one. But thanks to the nature of lateral friction and its effect on tracking, a heavier kayak often performs markedly better across long distances, over long periods of time. By traveling straighter, the heavier kayak often gets you to your destination faster, with less effort. Certainly the difference in tracking is usually extremely small (often even unnoticeable), but over an extended distance, even a tiny improvement to directional stability adds up.
Let's consider how a tracking penalty of just a single degree would affect a hypothetical paddler who paddles non-stop, at a constant rate of speed, for 8 hours (480 minutes). In the figure shown below (not drawn to scale), Kayak One (blue) travels straight from point A to point B, whereas Kayak Two (red) deviates off-course by just one degree, and then turns straight toward its destination at the end (x = time lost to course deviation). All other factors being equal, Kayak Two will lose 8 minutes and 23 seconds to course corrections by the end of 8 hours!
Even with a GPS, the paddler of Kayak Two would probably never notice he has deviated off course. It's hard enough to see the difference in trajectory on paper (when the one-degree angle is drawn to scale), let alone in practice, when the kayak isn't erring conveniently in one direction. (A real paddler would "zig-zag" imperceptibly toward his destination.) Nonetheless, the tiny penalty to tracking adds up to an extra 8 minutes and 23 seconds on the water! Now consider the reality that an empty or lightly-loaded kayak might easily suffer a two-, three-, or four-degree penalty to tracking (still barely perceptible even on GPS). Over an eight hour period, the lighter kayak will lose approximately 17 to 25 minutes (possibly more) to course-correcting efforts. That's already more than enough (from this one factor alone) to negate the 16-minute speed advantage which the author of "The Lightweight Secret" bestows upon the lighter kayak in his own 8-hour paddling example. Add in real-world variables like wind and waves (which typically exert a greater disruptive influence on a lighter kayak) and the advantage of weight should increase still further. Regardless, the point is clear: The extra effort required to propel a heavier kayak is often (though not always) more than compensated for by a reduced tendency to deviate off-course, a higher resistance to the effects of wind and waves, a less frequent need for corrective strokes, and a shorter (because straighter) distance traveled from point A to point B.
A Disclaimer and Closing Advice
In the interests of practicing what I've preached in this article, I should clarify that I am no expert in hydrodynamics, propulsion theory, or any other scientific subject which might be relevant to this discussion. My "expertise" (limited as it may be) comes solely from years of independent reading and online discussions about these subjects. Even then, I don't claim to be anything like an authority on the subject. My goal is not to prove that a heavier kayak is "always" faster and more efficient than a lighter kayak. To do so would be as ridiculous as it is for "The Lightweight Secret" to argue the opposite. There are simply too many variables in play for either conclusion to be "always" true. I broached this subject to expose the sophisticated form that myth and misinformation can take, and the scientific rigor with which it can assert itself as fact. Certainly, there are many other problems I might have noted with the author's argument (one being the very obvious confusion about the difference between "actual speed" and "speed made good"), but to press further would be to stretch the reasonable limits of my own authority. I'll leave it to others to fill in the more sophisticated reasons that a heavier kayak often (though not always) makes greater overall progress toward its destination than a lighter kayak might under the same, long-distance conditions subject to the same variables. For my purposes, it suffices to observe (as many of you have undoubtedly observed) that, for whatever reason, the heavier kayak does not always end up at camp later than it would have under a lighter load. Sometimes it gets there first.
Despite the complexity of the preceding discussion, the reality is that every kayak has an optimal weight range at which it will perform best for a specific paddler, using a specific paddle, with a specific paddling technique. Rather than try to master the dense scientific explanation behind this reality, it is much easier (and far more useful) to simply experiment with the way that weight affects your kayak. Try adding and subtracting cargo until you find the ideal weight range that feels best to you. Eventually, you'll discover a winning combination. Ironically enough, given the nature of subjective preference, the weight range you prefer may not actually be the weight range which technically yields the "best" performance. (Some people may prefer a boost to initial stability over a boost to efficiency, and so on.) Regardless, expeditioners should never lose sight of the big picture (actual progress toward your destination), and should resist myths like "better performance requires you to shed pounds," or "a higher actual speed always amounts to better overall progress." Don't let the truth get lost in the details, the data, or the slippery logic. Exercise your right to inquire and doubt.
[Editor's Note: The preceding discussion of weight is presented in more condensed form in the article, Weight, Drag, and Performance.]
A Poor Defense (appended March 2006)
Since this article was posted, the author of "The Lightweight Secret" has added a brief paragraph which tries in vain to deny the rebuttal I outlined above. In a new section entitled, "Anecdotes Against," he writes:
This ridiculous effort to equate my critique with some nonsensical statement about smokers can hardly be called a defense. Far from "outrageous," the scenario of a lightweight paddler in a high-volume kayak is quite common. A quick glance at the commercial market will immediately confirm that hundreds of kayak designs tout load capacities nearly double the likely bodyweight of an "average-sized" paddler. Consider the capacities of these four kayaks, ranging from "recreational" to "high-performance touring":
Granted, these are maximum capacities which may be rated as much as 50 to 150 pounds heavier than the ideal cargo weight for each kayak. Yet even the adjusted "ideal" capacities would far exceed the reasonable bodyweight of an "average-sized" paddler, plus gearespecially if gear weight is shaved down to the minimal level the author of "The Lightweight Secret" advocates. Making matters worse, notice that the two models with the most reasonable capacities (the Blackwater and the Loon) are not even designed for long-distance tripping, yet their capacities remain surprisingly high despite the unlikelihood they would ever be loaded far beyond the paddler's bodyweight. Remarkably, these were the first four kayak models I could find (in a 5-minute search) which listed their "max capacity" in their statistics. With more time and information, I'm sure this list would grow to fill many pages. Regardless, this cursory research shows the very real probability that many paddlers will paddle a kayak designed to accommodate an ideal capacity much greater than the actual load. In such cases, added weight is as likely to improve performance as it is to degrade itand reducing weight may actually be counter-productive.
Part of the problem, I think, is that the author of "The Lightweight Secret" assumes that "outrageous" examples like a 125-pound paddler in a 300-pound-capacity kayak must pertain only to those rare cases of folks who fell victim to poor salesmanship, inexperience, or bad luck. Yes, in my original article, I did suggest that some paddlers end up paddling unnecessarily high-volume kayaks because of ignorance, marketing interests, or bad advice about choosing a kayak. (I also pointed out that this problem has improved in recent years thanks to a wider variety of designs and increasing awareness as the sport grows.) But it is a serious mistake to assume that excessive kayak volume is always a function of involuntary or unfortunate circumstances on the part of the paddler. In truth, the "over-sized kayak problem" is less a problem than it is an unavoidable realityeven for those paddlers who know how to size a kayak properly. Why? There are many reasons, but I will give two: First, the cavernous storage and tremendous reserve buoyancy offered by high volume designs can be extremely desirable to some expeditionerseven those who have no intention of filling all that storage space up. Second, because some degree of compromise is inevitable due to the varying demands of paddling. Consider this: Even if "Ultra-Light Bob" could shave ounces and get his total body-plus-gear weight down to, say, 190 lbs. for this trip, he still might choose (that's right, choose) to buy a much higher volume kayak in case his next trip will be twice as long or require him to carry additional (perhaps unforseen) equipment. That is the practical reality for a kayaker who can only afford one kayak, yet who plans to paddle it under widely varying circumstances.
Ironically, a separate article published at Nessmuking.com (the website hosted by the author of "The Lightweight Secret") also confirms the validity of these concerns. Writing about stitch-and-glue boat design, Tom Gerds reports: "While my Kevlar tandem is most excellent fully loaded it shows much too much freeboard when used empty with two paddlers. It is excellent for its intended purpose the BWCA trip fully loaded but performance and enjoyment suffers the rest of the paddling season for which it is used most often, just one of the compromises we all must make" (Gerds, Nessmuking and Stitch and Glue Boat Building May 26, 2007).
Still not convinced? Consider this: Even in a perfect world, where every paddler could own 100 different kayaks (each tailored to suit 100 different payloads and purposes), many paddlers would still choose to paddle a kayak with superfluous volume. Personally, I prefer the motion and ride of a high volume kayak. My own beloved Perception Eclipse (the older kevlar design, built on the legendary Sea Lion hull-form which has influenced so many other designs) has tremendous volume, yet performs extremely well in all conditions and rides much higher-and-drier than most low-volume designs. Whatever the scenario, the point is obvious: Because many people paddle a kayak designed for a capacity well above their weight, it is often counter-productive to "lighten the load" the way the author of "The Lightweight Secret" advocates. It is certainly not a "fact" that the lighter kayak will necessarily get you to your destination sooner or faster than a heavier one.
Enough about weight and volume. Let me remind the reader of the original topic of this article: "Myth and misinformation in the online paddling community." Notice the reaction this article had upon the author of "The Lightweight Secret." I laid out a clear, fair, well-reasoned rebuttal. I even included charts and graphs to support my claims, since the author seems to value statistics and numbers so highly. But observe his response: Did he rethink his logic and revise his claims? No. Did he do competent research into the realities of oversized kayaks and varying capacity needs? No. Did he clarify his position with practical advice about sizing a kayak for a particular application, weight, or trip duration? No. Instead, he gritted his teeth and wrote another ill-conceived paragraph touting the "factual" nature of his claimsan effort supported by a rather thin analogy to the health concerns of smokers. What's worse, he calls my plain anecdotal evidence "outrageous," yet sees no trouble with making flat generalizations like: "Most paddlers switching from traditional camping methods to lightweight methods usually save around 25 pound[s]" (Hansel, "The Lightweight Secret" March 17, 2006). I would love to see the "data" he gleaned from "most paddlers" to come up with that "scientific" number.
Perhaps in response to my concerns, he also added the following remark as a catch-all defense:
This might have been sensible advice, had it been explained. Instead it is tossed into the mix with the same carelessness that typifies the rest of the author's logic. Notice, there's no caution about sizing a kayak for the greatest anticipated load, nor any acknowledgment that trip duration can dramatically affect the required cargo-to-capacity ratio. There's not even an effort to clarify that KAPER and FREEship! aren't designed for the uses to which he puts themjust a vain effort to defend the accuracy of their data by calling them "the best we have." (Best who has? I doubt NASA or MIT would agree.) If I were to borrow his smoking analogy, I might say this: Calling your data "factual" just because it comes from the "best" free software you could find on the Internet makes about as much sense as telling a smoker they have cancer because you can smell it on them. Oh, I know your nose may not actually be a precise instrument designed to detect cancer, but it is, after all, "the best you have." (wink)
© 2006, Wesley Kisting