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Comment by tormeh | Hacker News Reader

What I don't get is why one oar is rotated 90 degrees off the other one. It means whenever I use these double-sided paddles I have to rotate them ever so slightly whenever I make a new stroke. It's annoying and I don't understand why it's done. Does anyone know?

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90 degrees reduces the wind pushing the upper blade. Feathering the blades to 60-80 reduces wrist strain (in novice paddlers, who aren't used to the movement) but makes the top blade more susceptible to catching the wind.

And if you play canoe polo, you'll want it to be exactly 90 degrees so the ball rebounds predictably when you block the ball with the paddle.

My words will fail to describe how much I love your comment.

Not only is your comment accurate, but also characterizes your background knowledge in ways I doubt a master author could accomplish in so few sentences.

Human memory is a strange and wonderful thing.

Reading the article and comments brought back floods of memories. Of the exact circumstances when I bought each of the paddles I've owned [I've been kayaking for 35 years, in most disciplines, in 3 countries. So I have bought a lot of different paddles...]. Likewise all the trips, marathon races and canoe polo tournaments in bad weather when wind gusts tried to snatch the paddle out of my hands.

As a kid I used a non-offset paddle (it was paddle you could disconnect, so that was easy enough) and then switched to 90 degrees. Having picked up some paddles two years ago that can be attached with variable angles I found something less than 90 degrees to be more comfortable. My kids and wife all prefer the 90 degrees. I guess it comes down to personal preferences. I never did real long distance sea kayaking so, mostly lakes and rivers and some easy white water when i was a lot younger.

The movement of paddling has a natural rotation of the shaft when you raised the fixed hand for a stroke on the other side, it's quite straightforward to figure out sitting and mimicing the movement.

During this movement if the blade aren't feathered at all you have to compensate with some bending of the wrist. The amount of rotation of the shaft induced depends on how much you raise the hand/elbow, and so is fairly dependent on your style of stroke. This is the main way I think should be approached feathering: how much vertical do you intend to paddle? From there the angle should follow to optimize for the least amount of wrist twisting.

In general paddling very vertical will come with more angle in between the blades. I practice slalom and use to have 70-80 degrees crossing, but I tend to paddle less vertically now (aging? Lack of training?) and I'm down to 60 degrees comfortably now.

I have never believed this argument. In particular, I, and my bones, joints, etc, are approximately symmetric under left-right reflection. This means that I am not chiral, and I would expect an optimized paddle that I hold, symmetrically, in two hands, to be similarly non-chiral. (It’s a paddle, not a oar!)

More concretely, if some biomechanical factor made it a good idea to rotate the top of the left paddle forward θ degrees at the start of the left-side stroke, I would want to rotate the top of the right paddle forward θ degrees at the start of the right-side stroke. But with a feathered paddle, one of those thetas is positive and one is negative.

This is wrong in a way that used to bother me deeply whenever I kayaked. I would unfeather any unfeatherable paddle I used to restore proper symmetry.

I suppose what’s really happening is that people feather to reduce wind resistance or because that’s how they learned, and once they’ve learned it, it feels natural.

I would be willing to believe that feathering either direction is somehow biomechanically superior to not feathering at all and that the symmetry is broken arbitrarily, but I would want to see evidence :)

The asymmetry is compensated thusly: when you feather your paddle, you should grip in only with your dominant hand. It should rotate freely in your non-dominant hand.

Your wrist movements can then be symmetric -- your non-dominant wrist is free to move as you please.

And because you are free to set the feather as desired -- you can set it in such a way to minimize the rotation required of your dominant hand (and, per the above, non-dominant hand) to transition from one half of the stroke to the other.

Last I remember looking into it is the hard 90 degree offset is for wind resistance in open water.

This is why it's done but still sorta of strange to me that this was the way I was taught by camp instructors - even though we never were going for speed. Feels a bit like learning how to ride a bike with one of those aerodynamic helmets even if you aren't really ready to learn racing technique yet.

https://www.sportsperformancebulletin.com/wp-content/uploads...

It's not just racing. Feathering paddles can be really useful generally if wind picks up and you're actively fighting it. Otherwise you're dealing with a lot of resistance with the paddle blade in the air. And I assume there are instructors who just want to instill feathered paddles as the norm you should expect.

I generally disagree but lots of people with more experience than I have don't.

Yes. It's called feathering.

In general, I prefer to unfeather my paddles. (Many good paddles can be adjusted--modula small surface area Greenland paddles.) But there's also an argument that you shouldn't change your paddle orientation so that you can do bracing and other manoeuvres by reflex.

See my comment downthread [1]. You should grip a feathered paddle using only your dominant hand, letting it twist freely in your non-dominant hand. The paddle will then tend to orient itself correctly with minimal wrist movement. (This is probably more true of 30-45 degree feathering than 90-degree.)

[1] https://news.ycombinator.com/user?id=colanderman

My instructor said 90 degrees is an old school. Nowadays people do like 25 only.

in whitewater at least, 45 deg became the norm 25 years ago (except for slalom where closer to 90 was normal). Then it shifted further and now 30 is pretty much standard though 0 and 45 are not unusual.

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