CWTA - Kayak Basics - Kayak Paddle Blades

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Kayaking Basics

Kayak Paddle Blades Basics

Blade Size

Blade size is analogous to the size of gears on a bicycle; the larger the front gear, the harder the pedaling -the faster you go.

Large blades are meant for powerful acceleration and strong maneuvers. Like a longer shaft, a bigger blade area lets you apply more power, but also demands more effort on each stroke. Bigger blades are typically designed for paddling at more vertical angles. They appeal to those who want more immediate response from their paddle strokes.

Smaller blades are best used for paddles used in cruising and less fatiguing strokes. Smaller blades don’t transfer power as quickly, and need to be paddled at a higher stroke rate to achieve the same speed as a larger blade. But, they demand less effort per stroke. This may be easier on wrists and shoulders, especially when paddling a heavily loaded boat. Smaller blades are usually designed for use at near horizontal angles.

Blade Shapes

Blade Shape

Okay, there's a lot to cover in this one. There are three distinct aspects to blade shape:

Blade Outline – Looking at the blade flat on.
Lengthwise Curve – Looking at the blade from the side of the paddle.
Cross Section – As if you cut the tip half of the blade off and looked at the cut edge.

Blade Outline:

Most flat water (touring) kayak paddle blades are asymmetrical in shape, where most white water kayak paddle blades are symmetrical.
White water paddlers are learning, though, and more asymmetrical white water kayak paddles are being developed and marketed all the time.
Draw a line down the center line of the paddle shaft, through the center of a blade.
If the blade halves on either side of the line are the same (actually a mirror image of each other), that blade is symmetrical.
If the two sides are different, the blade is asymmetrical.
Wider blades (6 to 8 inches or more) supply greater resistance and are considered more powerful for acceleration than narrow blades, but the added width can cause more strain on wrist, arm, and shoulder tendons.
So-called touring designs, such as traditional Aleut- and Greenland-style paddles, have long, narrow blades (typically less than 5 inches). These paddles tend to have slower acceleration and less overall power, but they are less fatiguing, especially on longer trips in loaded kayaks.
Whitewater blades tend to be shorter and wider than their touring counterparts in order to provide power and grip in aerated water.
Touring blades tend to be longer, narrower, and smaller, for a smooth and efficient paddling stroke that can be maintained all day. Smaller blades are easier to control in the wind.

Asymmetric Blades

Asymmetric blades, common on many sea-kayak paddles, have less blade surface on the portion of the blade below the line of the shaft.
As the blade enters and moves through the water at an angle, torque is reduced by exposing each half of the blade face to equal amounts of pressure.
This balances the load along the centerline of the blade face, reducing the paddle's tendency to twist in the water and improving paddling efficiency.

Almost all touring kayak blades are asymmetrical. Asymmetrical blades are shaped differently above the paddle shaft than below it. This ensures that when the paddle enters the water at the intended angle, the submerged blade surface area is equal on both sides of the shaft. If the surface areas, both above and below the waterline, were not balanced, the blade would tend to twist and flutter as it was pulled through a stroke.

Asymmetrical blades range in shape from fat ovals to long thin quills.

Short, wide blades provide power and suit those who like an immediate transfer of energy with each stroke.
Long, narrow blades reach deep beneath turbulent water to obtain better leverage against calmer water below. They provide a gradual application of power and catch less wind, even when paddled un-feathered. On the downside, quill blades are less forgiving of a miscalculated angle during sweeping or bracing.

The two blades indicated above are fairly typical shapes. There are lots of different symmetric shapes being made today, as well as many different asymmetric shapes.

Symmetrical Blades

symmetric paddle blade

Most modem, paddle blades are both dihedral and spooned slightly.
The former reduces flutter (rapid side-to-side twisting motion) and sideways slippage by encouraging the water to flow off both halves of the blade face evenly; the latter provides more power by holding the water.
Racers use an extreme design called a wing with a pronounced scoop to its blade; this provides a more positive "bite" on- the water during a forward stroke but can take some getting used to, especially with other strokes.
Symmetrical blades are usually more forgiving of mistakes than asymmetrical blades for the less aggressive "drifter" type white water paddlers. Very long, skinny blades do not offer as much grip on the water as shorter, wider blades when using a standard modern kayak or canoe stroke. Except for some experimental trials in very specialized racing applications, all canoe paddle blades are symmetrical.

Asymmetric Blades vs Symmetrical Blades

For either white water or sea kayaking, asymmetrical blades offer more and better boat control than symmetrical blades, especially for the aggressive paddler.
The distinctions between symms and asymms in the physical feel during use might require a bit of acquired expertise for most paddlers to notice much difference.
Deep water paddlers will notice the difference more than shallow water paddlers like kayakers into white water "creeking."
Properly designed asym blades seem to feather easier than symms for transitional strokes.

Lengthwise Curve:

A paddle blade can have either a flat or curved shape when looked at edgewise, from the side of the paddle. Varying amounts of curve are possible, and different places on the blade might have different amounts of curve. The biggest advantage of the flat blade is forgiveness for beginners, and the biggest disadvantage is probably lack of grip on the water that more advanced paddlers prefer. Most kayak paddle blades (midpriced and more expensive paddles) are curved, but there are exceptions. Most canoe paddle blades (every price range) are flat, though many prominent whitewater slalom racers in both open and decked C-1 are now using curved blades.


Blade Flat Lengthwise	Blade Curved Lengthwise

The above two pictures show a flat blade and a curved blade from the side. A blade is either flat or it's curved, and varying amounts of curvature are possible. The above curve is exaggerated greatly.

Blade Cross Section:

Several different cross sections are available on paddle blades. Typical sections are flat, spooned, dihedral, and wing. The ribs indicated below are typical, some blades may have them on one or both sides, and other blades may not have any appreciable ribs. As a general rule (there are always exceptions) ribs on the side of the blade facing the back of the boat (powerface) have a detrimental effect, and ribs on the other side of the blade (non-powerface) don't matter very much.


Flat Blade Above	Dihedral Blade Above

Spoon Blade Above	Wing Blade Above

The above cross sections are typical, not specific.

A flat blade is flat, but a given blade might be more spooned or more dihedral than another spoon or dihedral blade.

The dihedral, spoon, and wing above are exaggerated a little for clarity.

The amounts of spoon or dihedral will probably vary in different parts of the blade surface.

There might even be combinations of two or more of each section on the same paddle blade.

For instance part of a blade is flat and the rest is dihedral, or there could be a little bit of spoon in an otherwise flat blade. The side of the blade that faces the rear of the boat (power face) points to the top of the screen in the above drawings.

There are advantages and disadvantages to each sectional shape.

Both spoons and wings offer a very powerful stroke, but are also very difficult to control during a stroke, especially for beginners.

Dihedrals can be very forgiving, but many are so forgiving that they limit the capabilities of the paddler after the beginner learns the basics.

Blades that are essentially flat across the face seem to offer the best balance between forgiveness, power, and control.

To make a distinction between curved and spooned blades here. A true spoon blade is curved across the face, as well as lengthwise, like a soup spoon. Some blades are curved lengthwise, but are flat across the face. A curved blade is not necessarily a spooned blade. In fact, most blades that are called spooned, are not. A true spoon will hold water on the surface, where it will roll off of a flat blade that is curved lengthwise.

Kayak Paddle - Feathered or Unfeathered?

A feathered paddle has the blades rotated at an angle on the axis of the shaft. An unfeathered paddle has its blades on the same plane.

Feathered blades offer less resistance to a headwind, while unfeathered blades are best in a wind from the side.
Unfeathered blades also require less wrist and forearm motion and are less likely to cause tendonitis.
Each type works well under different circumstances and neither is best for all conditions. The best solution is to purchase a two-piece breakdown paddle that adjusts to either feathered or unfeathered position and stick with the one that feels and works best for you.

Winging It

With a conventional paddle, the blade is inserted in the water near your ankles and serves as an anchor toward which you pull your kayak.

A wing paddle features a blade shaped more like an airplane wing. When moved laterally through the water, it creates forward lift, which pulls the boat along. The wing tracks very solidly in the water, and also encourages torso rotation and straighter-arm paddling.

With these paddles, low braces work, rolls are fine, and sweeps are okay, as long as you only do the first half. The downside is that if you try a high brace or a sculling stroke, you're likely to swim. Steering corrections made at the end of a stroke don't work.

Most recreational or touring paddlers will be happier with a conventional blade. For those who demand a couple of percentage points greater speed at the cost of some stroke versatility, the wing is an option worth exploring.

More About Kayak Paddle Blades