By Paolo Santoné
English (poor english) version.
I usually write for professionals, that is people who, in one way or another, with different levels of experience, already belong to the world of “paddle” sports. However, it happens more and more often to see, on dedicated social groups, the questions of complete newbies, who intend to approach our world, perhaps with the purchase of a boat, but with complete confusion about what to buy and why.
I therefore decided to dedicate a series of articles to what are the things to know and the requirements to keep in mind in order not to be disappointed by an incorrect purchase. Of course, the preliminary advice to attend a course is always valid, so that you can try various models and receive adequate training. But here, unfortunately, the first obstacle is encountered: not all those who offer courses or lessons are qualified, and even among the qualified, not all have the same qualification and the same preparation ... We must therefore pay close attention also in this case; recently the federations or associations that offer their qualifications and their training courses have multiplied, but not all of them offer an adequate level of preparation. Leaving aside this topic, however, which may be dealt with in another article, let's focus on the choice of the boat.
The first, absolutely very first thing to know when thinking about buying a canoe or kayak is: what use do I want to make of it? Every canoe or kayak, as well as every bicycle, pair of skis or car is designed for a specific use. Some explicitly exclude a certain use, others allow it, but with very poor or disappointing results. To explain myself more clearly I will give some examples: it is practically impossible to go downhill on a downhill path with a road bike or to tackle a dirt and bumpy path with a sports car; vice versa it is possible to go on the motorway with an off-road vehicle, or on the road with a bmx, but the results will certainly not be ideal: greater fuel consumption or fatigue, less efficiency and speed. In paddle sports it is the same thing: it is practically impossible to run a steep and maneuvering Alpine or Apennine stream with a 6m surfski. or with a sea kayak equipped with a keel or a Polynesian outrigger canoe; vice versa I will be able to splash around in the lake or at the sea with a kayak or a river canoe, but at the cost of a great effort in moving forward, in maintaining direction and in countering the action of the wind. Each boat is made for a certain environment and performs at its best in that situation. There are compromise models that can cope with different situations quite well, but of course they will not have the performance and efficiency of specific models. It is therefore absolutely essential to understand before a purchase which will be the prevailing area of use, and any out of program, and to adapt one's choice to the models that have the appropriate requirements.
Now let's see what characteristics the boats must have in relation to the environment of use; in this roundup we will not consider models intended for competitive activity, designed for a specific use and expert practitioners.
In the first place, even without resorting to formulas and coefficients, it will be good to specify that the speed and efficiency of a boat is always directly proportional to the length and inversely proportional to the width. The ratio between width and length is therefore very important for the efficiency of the boat. Having an efficient boat means not only going faster (relative quality that many may not care about) but being able to go further with less effort (and this is very important). He says: yes, but I want to train, working a little is fine with me. Okay, take a bucket and stick it behind the canoe, but don't paddle around in a bucket!
Since you cannot go below a certain width, because this would jeopardize the balance too much, it is evident that if your intention is to make long excursions in a lake, sea or calm river, you will have to orient yourself on a boat that is not too short. .
Of course, the length (together with other features that we will see) makes the boat more bulky and difficult to maneuver, and this is why shorter models are used where speed of maneuver and handling are crucial.
Other factors affecting speed, directionality and maneuverability are the design and the longitudinal curvature of the bottom. We will say that a hull is directional when it tends to continue in a straight line on the set course, while if, by stopping paddling, it tends to turn, we will say that it is more maneuverable. A hull with a flatter keel line, i.e. one in which the draft is uniform along its entire length and the ends are submerged, will be directional. Conversely, a hull with a pronounced longitudinal curve and the ends raised out of the water will turn more easily.
Regarding the cross section, the bottom can be rounded, flat or with a flattened V section, or variations and hybrids of the three types. The semicircular or acute V sections are very unstable and intended almost only for competitive use. For tourism, low-arched or V-shaped open-angle sections are used. Any longitudinal keel lines or ribs increase directionality, but they decrease efficiency.
Therefore, if I want a directional hull that allows me pleasant and not strenuous lake or sea excursions, being able to paddle easily without having to continually correct the direction, I will have to orient myself on a hull with a lowered arch or a lowered V, with little or no longitudinal curvature. (rocker), so that the ends are also in the water, and a fair length (from 420 to 550 cm. on average). You can also go down a bit with the length, but I wouldn't recommend going below 380cm.
If, on the other hand, I want a more manageable boat suitable for moving streams, I will choose a hull with a flat bottom or with a lowered arch, shorter (250 - 360 cm) and with raised ends. With this boat, however, at the lake or at the sea I will have a lot of effort and I will have problems keeping the course.
As for the shape of the bottom, we can still say that flat bottoms offer great initial (or primary) stability, and inspire confidence in newbies, but become more unstable when tilted to one side (secondary stability). Conversely, the arched or lowered V bottoms have a lower primary stability, and at first seem more dancers, but they acquire support by tilting the hull on the side so they have a better secondary stability.
We also keep in mind that an important factor for the efficiency of the hull is the reduction of friction. Since as we know the solid that has the greatest internal volume with the smallest surface (and obviously the smallest surface in contact with water means less friction) is the sphere, so a perfectly semicircular section is the one that guarantees the least friction (obviously we are talking about of displacement, non-planing hulls). Semi-circular section hulls are very unstable and are practically used only in racing, but a low-arched section is more efficient than a low or flat V-shaped one.
I also see from the questions that are asked on blogs, that many are worried about the problem of size: if it is a question of storage, certainly size can be a problem, but for transport reasons in my opinion (after almost 35 years of experience) I think weight is much more crucial.
In the next article we will deal with materials. Stay connected.
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