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?
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).
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:
= 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.