Swift Canoes & The Competition

By John Winters

In Partnership With Swift Canoe & Kayak

2394 Highway 11 North RR#1

Gravenhurst, Ontario Canada

P1P1R1

Scribd Online Database Series

December 2010

© 2010 Swift Canoe & Kayak/John Winters. This document is not to be printed, distributed, sold for profit, or used in any capacity outside the Scribd document database without the expressed written consent of Swift Canoe & Kayak and/or John Winters.

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Swift Canoes and the Competitionby John Winters

The unusual appearance of the first Swift canoes met significant resistance from buyers accustomed to traditional Canadian boats and de-tuned racing boats offered in the US. With nothing for comparison, paddlers grew to accept these shapes as the only acceptable shapes. The introduction of our boats altered that view and more and more paddlers now recognize the benefits of canoe designs based upon sound hydrodynamic principles. You will find convincing proof of this attitude among the growing number of Swift clones that claim to be “as good as” or “like” Swift canoes. We have always had to explain to customers why our boats differ and what those differences mean to them but now we face the added task of explaining the superiority of our boats over boats that look very much the same to the unpracticed eye. I hope this brief explanation of why our boats differ from the competition will help you when you talk with customers.

Few customers care about the technical aspects of the design (they probably wouldn't understand them if you told them) but they do like to know that we did our home work. To convey this you must stress the professional design our boats using the latest ship and yacht design technology. No one can learn the nuances of fluid dynamics in a few hours but the simplified explanations that follow should help you. Occasionally a customer will want more detail. If so, be honest, admit you don't know the answer and tell them that we have professional designers because they know the answers.

Displacement

We call the total weight of the boat and its contents the displacement. Customers , however, want to now about the load the boat will carry. For all practical purposes we can treat displacement and load as equivalent since canoes don’t weight very much compared to the weight of the paddlers and gear. All boats have an ideal displacement whether the

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builder knows what it or not. We know the proper displacements of our boats because we design around a displacement goal based upon the expected size of paddlers and the amount of gear they will carry. In other words, we know the destination before we start not after we get there.

Our boats perform best within a specific range and you should guide the customer into a boat that suits their weight. Displacement may be a foreign concept to most paddlers accustomed to thinking in terms of length but length is only part of the equation. I believe that the first question you should ask a customer is "How will you use the boat?" and the second is "How much will everything weigh?". The answers to these questions will usually narrow the selection down to three or four boats.

The graph in our catalogue should help you. Notice the overlap between boats and the absence of a sharply defined point where a boat suddenly becomes a water pig. Weight affetcs performance in a gradual manner. So, you can be flexible to some degree when dealing with the customer. From a safety standpoint, however, larger provides more safety than smaller. A larger under loaded boat may be less handy to paddle but an overloaded boat may be dangerous.

A word about “capacity”. This useless figure comes from regulatory bodies who did not know any other way of assuring boat safety. Capacity refers to how much weight a canoe will carry and still have six inches of freeboard. You need only load a canoe that way (any canoe) and paddle it to see the silliness of such an idea. Even better yet, try portaging that much weight.

Performance

By "performance" we mean the ease of paddling. We do not build racing boats. We design our boats to be efficient at normal paddler effort. (The average paddler produces about 0.10 horsepower on a continuous basis. Top level Olympic athletes produce about 0.5 horsepower.) The important thing is not speed but speed versus energy. Five to six kilometers per hour is a good cruising speed and we design for efficiency in that range. Three major aspects of design influence efficiency — Prismatic coefficient (the distribution of volume along the hull), Fineness coefficient (a measure of the displacement versus length), and the wetted surface coefficient. (It is not essential that you understand what these mean but it is important that the designer does). Millions of research dollars have been spent to determine the ideal coefficients and we take advantage of the research to produce efficient, safe, and seaworthy boats.

Obviously it would be nice to know how a boat will perform before we build it. We find out by using KAPER, a performance prediction program created by me. The only program of its type designed expressly for

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mathematically predicting canoe and kayak performance it is used by Sea Kayaker magazine for their boat reviews. With KAPER I can analyze a design (those of competitors as well as my own) and adjust the hull shape to optimize performance. Recently I have begun using another program called Michlet written by Leo Lazuaskas of the University of Adelaide to augment KAPER.

How fast will our boats go? The proper questions would be, How hard can you paddle? Contrary to popular belief canoes have no “top” speed. Many believe that “Hull speed” represents the top speed but it serves only as a term of convenience for naval architects. It relates to the point where the length of the bow wave and hull's effective waterline length approach being equal. If you are asked about the hull speed of our boats you need only answer that all of our boats can easily exceed “hull speed” when they are properly powered but that the average paddler will never even come close.

Stability

We can tell you how stable our boats are and how they compare to the competition but that won't help you or the customer. The only thing that matters is how the boat feels to the customer.

So, how do we design for stability? First we define our target customer’s requirements and then select existing boats that the target paddler likes. We then analyze these boats to see what type (shape of the stability curve) the boats have and then shape our boat to improve upon the competition. As you know, Swift offers boats that have high stability at small angles of heel (often called initial stability). These boats (The Algonquin series and new Royalite series) suit casual paddlers. A second group of boats with greater emphasis on dynamic stability (How the boat feels as it is heeled by waves or paddlers) to better suit more serious paddlers.

In this second group of boats we create shapes that will have smooth motions regardless of conditions and will have positive righting moment right up to and beyond the swamp point. This provides an extra margin of safety in severe conditions. Most often you will hear such boats referred to as being “predictable” which means there will be no abrupt changes in how the boat feels as it heels. I know of no easy way to explain how I do this other than to say that I superimpose waves of all sizes over the hull in the design phase. Then, I alter the shapes to assure smooth, uniform stability curves for each wave type and size. No one feature makes a boat feel good. It is a blend of section shape, waterline shape, and beam.

Controllability

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Here I would like to introduce you to a word that may be unfamiliar to you — controllability. Most often we talk about maneuverability and tracking as if they were separate and exclusive. The idea of a boat that tracks well and turns well at the same time seems contradictory and people have a bit of trouble wrapping their minds around it. Many builders and paddlers still believe that a boat must have a straight keel line in order to track straight but must be rockered at both ends to be maneuverable. This simplistic idea might be nice for conversation but controllability is a function of how the Block coefficient and profile coefficients are blended. (We call the ratio of the boat's displaced volume to the volume of a block with the same length, beam, and draft the Block Coefficient). Profile coefficients relate to something naval architects call “stability roots" that require a chapoter in a book to explian). A boat can have a low profile coefficient conducive to good maneuverability and a low Block coefficient conducive to good course stability. In this way (within limits) we can design a boat that turns well and tracks straight.

Few canoe builders have even the vaguest idea what these factors mean or that they even exist. Fewer still will invest in a ship design program that calculates them much less go back to university to learn about them.

Seaworthiness

A boat that will not survive severe conditions is not much good to a wilderness paddler. Our boats have carefully determined amounts of flare and ample freeboard to keep them dry under most conditions. They also have something else — paddling ease. We do not normally think about paddling ease as an important part of seaworthiness, but there is little value in staying dry if you cannot paddle to safety. By superimposing the hull against waves of all types we make certain they will not plunge too deeply into waves and yet will not have excessive freeboard and high windage. Here again the computer shows its worth. The calculations to do this kind of analysis can take days with a hand held calculator but are short work with the proper programs and a powerful computer. Nevertheless, a certain amount of “art” remains in this.

Paddling Boats

All boats feel differently when loaded. For this reason alone people should test boats loaded just as they will use them. More importantly it pays to tell customers what to expect. Our boats look different and paddle differently. The buyer that knows what to expect and what to look for will be more favorably disposed to liking the boat. You may have tons of

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experience and a boat may feel just fine to you. Your customer, on the other hand, may have very little experience and the same boat may feel horrible. Remember you must sell the customer not yourself.

High performance boats require paddlers who either have good skills or intend to get them. This is a major difference between our boats and those of our competitors. We design to suit objectives and, in so doing, create boats that feel as if they had been custom designed to suit the paddlers. The third question I would ask a customer is, "How good are you now on a scale of 1 to 10?" The fourth question is, "How good do you expect to be next year or a year after?" If they answer anything below 5 to both questions then they have no business buying (and you have no business selling ) them a high performance boat like a Kipawa, Dumoine etc.

Looking at Boats

Fortunately our boats differ enough from most of the competition for visual comparison. Boat designers commonly say, “If it looks fast, it probably is." Our boats just plain look fast.

With the boat right side up you can point out the flare and how the volume is distributed fore and aft as well as vertically. You can explain how we keep the beam forward narrow to make it easy for the bow person to execute efficient strokes. The sheer has a smooth gradual curve forward of amidships to keep the boat dry (most water comes aboard just aft of the forward seat) and lower aft of amidships to encourage proper stroke mechanics.

Upside down it should be easy to see the asymmetry. Why asymmetrical? The technical reason has to do with something called the boundary layer but one should intuitively know that, if the bow pushes water out of the way, the stern must allow it to return with minimum turbulence. It should be intuitively obvious that a shape that does one thing well will not be the shape that does the other well (There are good reasons why cars and airplanes have different fronts from their backs). Also, most people paddle with the heaviest person in the stern so it only makes sense to make the boat fuller aft to support them. This is a good place to point out that no symmetrically built boat is symmetrical to the water for more than a few milliseconds. In other words, they are asymmetrical by accident instead of intent. We design the boat asymmetrical to begin with but do it for good reasons instead of by accident. A clever way to explain this is to say that a symmetrical boat has either two bows or two sterns. At least one end is always wrong.

Mind, this may not be important to those who paddle casually and simply want a boat that is stable and undemanding.

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There is more to asymmetry than just waterlines. Swift canoes have asymmetrical profiles as well as waterlines and have more rocker at the bow than at the stern. This is one reason why they handle so well with more response to control strokes by bow paddlers. Another point worth mentioning is the clean shape of our boats. There are no abrupt changes in shape to cause pounding or increased resistance. Extremely fine hollowed out bows and full cheeks may be attractive but they are not best for performance.

Features of Competitor’s Canoes

Plumb bows and sterns -- Aside from looking boxy, plumb bows lack the added buoyancy provided by the raked bow. Also the deep forefoot common to this type digs into waves and can cause broaching.

Tumblehome - Solo canoes benefit from tumblehome because it permits a more comfortable and efficient stroke. For tandem canoes, tumblehome rarely has any value. I say rarely because there are some special instances when tumblehome froward and aft can be useful. The paddling positions are already narrow enough for efficient strokes and the boat is heeled when paddling solo eliminating the need for tumblehome midships.

Keels - They add resistance, and restrict maneuverability. If keels are needed to improve tracking, the boat was not designed very well to begin with. Most often keels are used to stiffen the bottoms of cheaply made canoes and, in the case of our Muskoka series, to satisfy customers too pigheaded to understand the concepts.

Extremely fine waterlines -- You cannot fool water. The boat does not cut through water like a knife. It pushes the water both down and aside. This should be done gradually in both directions. Fine waterlines eventually have to widen into full cheeks and that means increased resistance and pounding in waves.

Extremely blunt or full ends -- These are good for stability but terrible for performance. Paddling one of these boats is noisy and noise is a good indication of inefficiency.

Sea Kayaks

Almost all of the preceding applies equally to sea kayaks. However, some unique aspects of sea kayaks deserve special mention.

The two centers of sea kayaking are Britain and the Pacific northwest. Both areas have developed their own style of boats and have promoted them strongly. The typical British boat is narrow with upswept ends in a

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pseudo Greenland style. They stress handling qualities and the purists will argue that rudders are superfluous although many require retractable skegs for directional stability. Proponents of the type will swear their boats are faster than any other kind although this is rarely the case. The west coast boats commonly have greater beam with greater stress on tracking and, occasionally, on surfing abilities. Most require rudders for control and directional stability.

The kayaks designed for Swift are a breed apart. We made no attempt to mimic native boats nor design boats that require expert skills to paddle comfortably. Because kayaking is a growing sport and most new paddlers are inexperienced we have chosen to produce boats that are comfortably stable and do not require expert skills. (This was written before I designed the "high Performance boats now being tooled at QCC so even Swift has succumbed to the pressure of "experts".

Rather than duplicate the preceding I will concentrate on those features of kayaks that differ from canoes and the reasons why we have chosen a different route.

Rudders

Many sea kayaks need rudders to provide directional stability and for maneuvering. It is often suggested that a rudder is essential to a kayak. Why? There are literally millions of canoes and few if any have rudders even though the single blade paddle is not the best straight ahead power. Maybe canoe designers know something kayak designers do not know. In any case, rudders are not necessary on our boats. That does not mean that one should never sell one. Occasionally a paddler will insist on a rudder but the boat doesn't need the rudder — the paddler does. In this case, sell it with one. It will do no harm. You should, however, point out the advantage of saving money, weight, and complexity by not using a rudder. Usually a person can buy a first class paddle for the cost of a rudder.

You should know something about rudders. Ours has a foil shape similar to those you will see on the tails of airplanes. We use this shape because the flat plate type used on most sea kayaks stalls when turned and this increases resistance and reduces the rudder’s effectiveness. We also use a stronger stiffer stainless steel rudder head. If you depend upon a rudder to steer the boat it should be effective and strong enough to withstand beaching, etc. Floppy rudders made from thin plate just do not make the grade. Why do builders make them? Because they are cheaper to make.

Hatches

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There are countless hatch designs and methods of sealing them. The VCP hatch has the best reputation for not leaking although they win no beauty prizes, cost more than most and detract from the appearance of otherwise attractive boats. The only people who actually need that type of hatch are those who paddle in extreme conditions and they would be much better off with no hatches at all. Our hatches are suitably watertight for normal use.

Recognize that no hatch is absolutely fool proof and always recommend that gear be stowed in dry bags.

Seats and Backrests

No seat or backrest that will please everybody. We have a reasonable system to suit most paddlers. If the customer expresses reservations about it the backrest, check out the adjustment. Most test paddlers will not bother to adjust things.

Hull Details

Our boats can withstand all reasonable sea conditions. There is no reason why a kayak designed for cottage use should not be seaworthy. We do not design un-seaworthy boats just because they might only be used on small lakes but that doesn't mean the boat can make up for stupidity or poor skills and judgment

Our boats do not have long overhangs. This hangover from traditional boats serves no purpose on a modern hull with adequate flare. Long ends do not add to seaworthiness. The reality is that the added weight reduces seaworthiness by increasing the tendency to pitch and pound. Long overhangs may have served a purpose on the relatively flat bottomed Greenland traditional boats that lacked volume but are not necessary on modern hulls.

We do not use the extremely concave waterlines commonly seen on the competition (Boreal, Necky, Wilderness systems etc.). These waterline shapes originated with designers who thought that the bow had to cut the water as if it were two dimensional. They also thought concave waterlines aft provided directional stability. Both theories are incorrect and such end shaping reduces the effective waterline length and increases wetted surface.

Chines are a hangover from traditional boats. The Inuit had only driftwood and skins with which to build boats and had no option but to build single and multi chined boats. Modern materials allow us to produce smoother shapes and using chines just because the Inuit had to use them is not good design. I should point out that chines can be useful on boats with

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very specific purposes but the typical recreational boat has no need for them.

Deck Details

Flat decks are the rage among traditionalists who assume they reduce windage. Unfortunately they are wrong. Wind tunnel tests show that the highly cambered decks are better at smoothing the flow of air over the boat. So good that racing rules were written to restrict designers from putting ever larger fairings on sprint kayaks. The higher deck also makes getting in and out easier. You will note that we flatten the deck on either side of the cockpit. This provides a lower surface for bracing against with the knees. Our latest deck configuration carries this one step further. By angling the deck at the edge we reduce the amount of "knuckle busting" that occurs when you stroke close to the boat. We also camber the aft deck. Flat decks aft are helpful for some types of rolling but we believe the added volume serves a more useful purpose.

Hull/Deck Joint

The joint used on our boats is typical of those used in the sailboat business for many, many years. It is strong, light, leak proof, and less expensive to manufacture. This joint is one reason our boats are such good value.

Cockpit

There are as many cockpits sizes as there are boats. Unlike the British who think everyone is undernourished and make their cockpits to suit little skinny people ours are sized to suit people of normal North American build. Smaller people are easily accommodated by installing padding on the vertical pillars in the cockpit.

Magic Numbers

You may have heard about and are probably wondering where all the magic numbers are. What is the “right” prismatic coefficient? Block coefficient, etc.? Well, there are none. Every boat and every requirement mandates something different.

Finally, nothing I say here about these boats will ever be as useful or informative as time spent paddling them. Get out in the boats. Not for just a few hours, but for days and in all conditions. The time will be well spent. It is nice being able to talk about the boats and how they were designed

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but the best salesperson speaks from first hand experience. Some of the best salespeople I have ever known do the most paddling and speak from the high ground of experience.

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