Which Blade Shape?
What I am about to say comes from almost two decades of competing in Down River Racing, marathon and ocean ski racing. I have no axe to grind, it is just what I have learned and been taught. I have listed different types of blades and their lengths below. These are blades that I used and I am still using today but this is not much use to you if you dont know my height, which is 6 foot or 182cm.
I do not use one blade for all disciplines as each shape has its own unique characteristics. Instead, I use a blade suitable for the type of kayak/ski I am racing and for the conditions. Just one additional comment which is that I am a confident paddler and I like to push the limits so my choice of blades will be ones that work well for me even in some hairy situations. I believe that confidence is vital to how I paddle well in all types of water conditions. I believe that the different shapes of the blades suit styles and water conditions and are therefore faster but I do not believe that there is a golden blade that will make you go faster than any other blade, that is just in your head.
There are two basic types of blade shapes. Parallel edge (some examples are Lettmann I, Stealth, Marathon, Rasmussen, Braca III & VI etc.) and the teardrop (Epic, Braca I, II & IV, Fusion, Russian the list is endless). Within the parallel edge blades there are a few with no offset and little pitch (Flite 5, Champion, Wildwater, Gutt are a few examples)
Down River Racing:
Ocean Racing Ski:
Some words of wisdom from various coaches.
"Too long paddles or too large blades means the paddler will not be able to paddle with good technique, and may change to bad technique to cope with using them."
"Too long paddles means the paddler will never be able to train explosively or with a high enough stroke rate. This will work against their desire to go fast, and hinder development."
"The right length is what is right for the individual paddler and the craft they use."
"If in doubt, paddle size should be smaller than larger and or paddle length should be shorter than longer."
Like many of us we can easily fall into that human trap that the decision we have made must be correct and to maintain this belief we then apply blinkers to shield us from anything that contradicts it. We just hate being proved wrong, right? So even for more seasoned paddlers it might be an idea just to step back for a moment and ask yourself is this really working well for me? Is my technique good enough to get the most out of these paddles?
Remember if you are starting out, you won't yet have the strength of the top paddlers so just like racing a road bike, you are taught to spin in smaller gears until you develop stronger muscles to push bigger gears. The same applies to kayaking. Cadence should be between 80 to 90 single strokes per minute at race pace, so adjust length and size of the blade to suit.
In summary, if you are starting out in the world of kayak racing then in my opinion the best balanced blade type is that of the parallel edge type. It is very predictable in all situations and will greatly help developing paddler's confidence. Once you are a confident paddler, go for your life with regards to blade selection.