Paddle Guide

Blade - Your blade is your prime mover, if your body is the engine then your blade is the propeller! To start, we need to ensure your blade is properly sized.
There are many different paddling styles and techniques. None of them are wrong, they have each been created to fill a niche or fulfill a requirement. Our discussion here will center around the high angle style of paddling which has evolved from aspects of Greenland, Inuit, White Water, K1, C1 and low angles styles of paddling.

The most important aspect of your blade, you paddle, is that it is sized properly.

There are many different paddling styles that require different design inputs to create a product to fit the needs of each style

Common paddling styles:

  • High Angle Touring
  • Low Angle Touring
  • Greenland Style
  • Wing blade
  • White Water

For this discussion we will discuss high angle touring blades as that is the style that I teach in our Paddle Canada Courses.

High Angle style paddles come in a couple different shaft options. Straight Shaft and Bent Shaft or Crank shaft. Bent shaft Paddles keep the wrist in skeletal alignment which results in less wrist and forearm fatigue because the bones in the wrist are lined up. With the bones line up there is less pressure on the ligaments and muscles as the load is more evenly distributed over the joint. Straight shafts are typically a much lower cost option. Many paddle shafts offer a blade offset capability which cuts down on the amount of wind the dry blade will catch.

Paddles come in many different materials with varying benefits to each:

Common Paddle Materials

  • Wood - Relative insulator, low cost, good axial strength.
  • Aluminum - Cheap, some axial strength.
  • Polymers - Good impact resistance, low cost, very flexible.
  • Composite impregnated polymers - higher strength than straight polymers and still retain the impact resistance.
  • Composites (Fiberglass, Carbon and Kevlar) - Very strong and very light. 

If you are looking to quickly link strokes, accelerate quickly and be able to very effectively support you and your boat on the water then the high angle style is right for you. The High Angle style suits itself to both the Bay of Fundy and many of our fast moving rivers and streams. To properly size the paddle most manufactures look at your height. But what if your torso and leg ratio don't fit that perfect mold that these manufacturers have in mind when posting their one size fits all graph? 

Sizing

In reviewing sizing charts for various brands and going back to high school trigonometry it appears as though the angle of a high angle paddle can be anywhere between 65 and 75 degrees off the horizon. This brings the paddle in close to the kayak creating less of a moment arm.

So to help figure all this out I've done some measurements on myself and my paddle. I am roughly 182.88 cm tall BUT my torso from my butt to my nipples is roughly 58.5 cm (I measure to my nipple line because that is roughly where the center of my paddle shaft sits when my blade is in the water at my hip and my dry hand is in front of my face).

Now we have to take into account that my butt is actually about 2 cm below the water line so we will subtract that from the torso height (because the measurement plain for my dry paddle half length will also be the water line) therefor total torso height will be 56.5 cm. I've measured my 210 cm Werner Ikelos paddle (as you guessed, its half length is roughly 105 cm BUT its dry length (from center to the water line) is roughly 60 cm (45 cm of the length is blade in the water).

A complected but effective way to figure out the optimal paddle length for your kayak would be to measure your torso sitting in a hard chair from your crotch to your nipple line. subtract the number of centimeters you figure your seat is below the waterline (I figured 2 for my set up) and then get out your handy calculator and plug in:
Your calculated torso height after subtracting seat to waterline distance divided by sin 70.
You will then need to add the actual wet blade length to that number to give you half your paddle length. Multiply that by two and you'll have your total paddle length.
One of the manufacturers we retail has come up with a bit of a graph to provide a quick reference to paddle selection. It is not the be all to end all authority on paddle sizing but it will give you an idea. Essentially the closer you bring the paddle to the side of the kayak the less torque you will induce into the kayak (this is even more critical on short, wide shallow recreational kayaks that are easily turned).
Torque, as we recall from our physics courses back in high school (I'm from Charlotte county and luckily managed to scrape through phys...oh wait no I failed it twice BUT did finish first in my college physics class when I actually applied myself later in life, but that is another story) well for those of you lucky enough to have passed physics class you'll remember that torque (T) is essentially force (force vector) F (measured here in lbs) x the distance pivot point and the applied force (moment arm) d. 
In high angle style paddling, the paddle shaft is kept close to the side of the kayak thus minimizing the moment arm (d). 
The formula T=Fxd can be applied to show how paddle length can effect torque.
I dont want to get into more complicated trigonometry but to keep it simple I'll say this: for every action there is an equal and opposite reaction. Those reactionary forces are called resultant forces or vectors (a vector because the force has a direction of travel).
In the the figure above I'm applying a force from my torso being rotated. That force is transferred through my arms into the paddle and from the paddle shaft into the water through the paddles blades (where the force is actually applied into the water). Thanks to Newton's third law we know there is a equal and opposite force applied to the kayak (Fr). It is the resultant force of the force I applied into the water, this is how we move the kayak forward much like a propeller on a ship.
The difference,however, is a ship's propeller is attached at its center line so the resultant force is completely forward on the center line. The kayak's force however is applied a distance away from the pivot point (our torso or the center of the seat) therefore the resultant force (Fr) will not be straight ahead it will actually be at an angle away from the center line as shown below.
The applied distance will make more toque (the foot in foot pounds of torque) but will result in more torque in the kayak which will have a tendency to turn the kayak.
So if I use a 210cm paddle (I'm 6' tall and have a fairly narrow kayak) (divide that by 2 as only half the length is used to the center line therefore 105cm) and I can create perhaps 100 lbs of force about the center line of the kayak we can figure out how much torque I am applying (keep in mind that the paddle is also near 70 degrees which decreases the actual distance away from the center line). Let figure out what d is:

We've determined in the figure above that the blade to the center of the paddle is a horizontal distance of roughly 20.2 cm and from the center of the paddle to the center of the kayak (I measured) is roughly 33.0 cm therefor d = 53.2 cm. 

The actual distance from the center of the kayak and thus the center of my seat is 53.2 cm give or take a few. Now if I apply my 100 lbs force (F) a distance (d) of 53.2 cm (or 1.7 feet) away from from the forces pivot point (my torso) then the resultant force (a vector Fr) will be:

Torque = Force x moment  

= 100 lb x 1.7 ft
= 170 ft lb

Because the force was applied off of center we have a vector that is off of straight ahead. What we've actually done is induced a little angular velocity into our kayak (we're slightly turning it). The longer the kayak is the longer the moment arm is that resists this force (and the harder it is to turn the kayak when we actually want to do it).

We can increase the torque we are applying to the kayak with a longer paddle but it will result in our course over ground being less and less a straight line and more of a sin wave (exaggerated). Thus one of the reasons for the high angle style of paddling. The shorter and closer to the kayak the paddle is the more efficiently we can apply a forward force.

Because a high angle paddle is placed in the water at a higher angle the blade shape can be slightly different (it doesn't have to be as long) resulting in a shorter and wider blade with slightly larger surface area. This larger surface area lends very well to quick adjusting strokes as a larger amount of water can be used as friction against the blade. Newton's Third Law tells us (for every action there is an equal and opposite reaction) this will result in more force being applied to our kayak.