Aleut Paddle Design

Last year I got to use an Aleut paddle for a while. What’s that ridge for? Why would someone prefer that paddle over a GP?

Good time to ask where Greyak is yeah ?
http://www.paddling.net/message/showThread.html?fid=advice&tid=953422

Aleut paddle
There is extensive speculation as to the reasons for features in native paddles and kayaks and much less certain information. For example what are the reasons for the bifurcated bow of a Bidarka? Lots of speculation and little certainly.



I have been using an Aleut style paddle since 2003 as my primary paddle. I made that one at the Skinboat school with Colin Livesly, Cory’s man friday at that time. I bought a second Skinboat School made paddle while I was there to keep as a model to make another should I destroy or lose mine. I don’t know the source of Cory’s design, but it looks similar to other Aleut designs on the web except that the center ridge appears a little less prominent on the Skinboat design. I have made 4 more a few years ago for people who were asking me where they could get one after trying mine. I have also made a number of Greenland paddles over the years.



My quick comparison of the two types of paddles are that the Aleut is somewhat more powerful and the Greenland is somewhat more versatile (the two sides are identical). I prefer the Aleut for paddles of any duration because of it’s power and a Greenland for rolling practice. Both styles of paddles are easier on my body than Euro blades. This is most noticable in my rebuilt shoulder. My euro blades have been collecting dust since I made the Aleut.



I’m presently starting to construct the Aleutian paddle seen on the web in the drawings by Renso Beltrame of Italy. It has a more prominent center ridge than the Skinboat School paddle. I’m curious as to how it will feel vs. the Skinboat School style paddle and which I will prefer.



Dave

I paddle with GP and Aleut
I started paddling with Aleut first and then added the GP to my selection. I haven’t used Euro for a few years.

Initially I thought that Aleut was more powerful but once I started to perfect the stroke and avoid noise (cavitation?) I found both very versatile paddles.

Prefer the GP for rolling (sculls beautifully) while Aleut is easier on long hauls where I don’t have to concentrate on a canted stroke. The ridge is the power face and it seems to help avoid fluttering beside adding strength to the paddle.

And for those that still think that traditional paddles are for show only I like to show them this short video of me surfing: http://www.youtube.com/watch?v=gE5MexuDsxE

Stagnation line
You mean ventilation, not cavitation, by the way.



Interesting that you mention reduced flutter with the Aleut. From a fluid flow perspective, the ridge on the power face should act as a fixed stagnation line - i.e. it marks the dividing line between flow that goes over vs. flow that goes under the paddle.



On a smooth power face, say on a GP that isn’t canted enough, the stagnation line can move around during the stroke, especially when pulling briskly. This will cause quick variations in how much of the water goes under vs. over the blade, resulting in lateral blade oscillations, i.e. flutter.



A properly canted GP (that isn’t pulled too hard) won’t flutter, as it is behaving like a proper airfoil. The asymmetry of its position in the water tends to keep the stagnation line fixed. If pulled backwards without the cant, it will flutter, however. The ridge on the Aleut paddle would tend to reduce flutter, regardless of its orientation in the water.



Euro paddles can flutter as well, but is a slightly different phenomenon, I think. I wouldn’t expect to see a stagnation line on a Euro blade, as the water spilling around the paddle is more of a 3D phenomenon (like an elongated smoke ring) than the quasi-2D flow around a long skinny Aleut or GP (one or two primarily parallel long vortices).



The flutter on a Euro should occur whenever the amount of water spilling around the blade changes markedly at some point on its periphery. I think this implies that it may be more sensitive to flutter, but I’d have to think about it more to be sure. Certainly there are many Euro paddles that employ dihedral or other sophisticated blade shapes to reduce flutter successfully. I have a very nice AT paddle that never flutters.

Greenland
paddle can be made to have as much …or more power than the Aleut. or the other around way too.

The paddle maker can make it so…there is NOT just one size of each.



So you actually should have said…that Your Greenland paddle (or the one you prefer) has less power than Your Aleut paddle (or the one you prefer).



Best Wishes

Roy

much better explanation than
much better explanation than mine, Carl.

I believe that you have the terms ventilation and stagnation used in the correct instances, while I express the “noise” that I get from a non canted GP incorrectly.

Thank you for elaborating and explaining those terms.

Greyak
Yeah, Greyak did a great on-the-water comparison a while ago, but I couldn’t find it.

Not incorrect
Thanks, the ventilation/cavitation switch is quite common, so no problem. It’s definitely true that both ventilation and cavitation create noise, so that’s not incorrect.

Good question
Greyak seems to have disappeared. I miss his contributions.

Tip design and flutter
I have been making/using/experimenting with a variety of traditional and modified traditional paddles for close to 20 years. Many years ago I was curious about the flutter variable between the Aleut and Greenland paddles, especially when used in a deliberate non-cant style. When used like this, the design aspect regarding the induced flutter intrigued me enough I felt it was worth some personal experimentation. I had a hunch that the tip design differences between the two styles may be a contributing factor. The following winter I made two basic Greenland paddles of similar WRC, length, width, thickness, loom and shoulder size. The only difference in design between the two paddles was the tip design. One paddle had the standard blunt Greenland paddle style end, the other paddle I shaped with a “V” tip of 90 deg.



The following paddling season I had a chance to take both paddles paddling for water trials. I had a GPS with me to verify a uniform speed when using both paddles. Both paddles I paddled with similar angles to the horizontal and with no cant, the intention was to induce flutter. After a series of trips it appeared evident to me that the paddle with the “V” tip had very diminish induced flutter as compared to the blunt end of the standard traditional Greenland paddle.



Now I can’t give anyone here an explanation in hydro-dynamic terms the true explanation for this varied phenomena. This was the best live experimentation process I could come up with at the time, and from my personal perspective it proved for me that a “V” point design diminished the likelihood of flutter. Consequently due to that experiment the majority of my paddles I have since created are of a “V” tip design, with the exception that the sharp point of the paddle is rounded to the arc of 25 cent quarter. I add the rounded end so as the end of the paddle when held in the palm of my hand when sculling is not an annoyance.



Chris Hess

This one?
http://www.paddling.net/message/showThread.html?fid=advice&tid=997074#997151

Paddle comparisons

– Last Updated: Mar-09-11 9:45 PM EST –

Chris, I have done a non-scientific paddle comparison also. In the last two years I bought two used Greenland 2 piece paddles. One (Feathercraft) has a noticeable center line and relatively flat sides going from the center line to quite narrow edges-sort of a thin diamond cross section. The second paddler has a elongated oval cross section and fatter edges. Both are about 88" in length and 3 1/4 width.

About ten times I have gone out paddling with paddlers from my club and had them try the two paddles, changing paddles about ever 5-10 min, for about 45 min-60 min. I didn't give them any information before or during the "trial" or even say it was an informal trial. At the end of the "trial" I just asked them which they preferred? All preferred the Feathercraft paddle shape. To my surprise I did too, and I had been paddling another paddle of the rounded oval shape (by the same paddle maker) whenever I chose a GP over my cherished Aleut.

Ron, I agree there are numerous factors that go into paddle performance and any shape can be made move or less powerful by varying those factors. My Aleut has somewhat similar blade area as my GPs (a guess, not measured) but has a very wide loom, so it does have a longer lever arm. The one I'm making presently will have a narrower loom, so I will be interested to see what difference I feel between them when paddling. I choose not to attempt scientific comparisons as I would rather spend my time paddling.

Dave

Interesting
I find this info about sharp points reducing flutter quite interesting. I imagine the point acts to anchor the separation line in place at the tip of the paddle, mitigating to some extent its ability to move around higher up on the paddle, which would reduce oscillations. Also, cutting away material at the corners reduces the moment arm over which unbalanced hydrodynamic forces can act at the paddle at the tip - pretty cool.

yep, now puff out each side
just a little bit to desired preference to gain a bit more catch or bite while still keeping it super smooth. Can even go wider @ the shoulders with this diamond shape.

yep, now puff out each side
Ahhhhh…, sounds like the Aleut paddle.

Yes, and if you want a stronger catch as with the Aleut as compared to a Greenland this is the way to go.

I have a paddle similar to what you describe. Besides a stronger catch during the paddle draw, the added end tip width area is also nice for added lift and support when used with a sculling recovery.



Chris Hess

kind of like the Mitchell Coastal
with a rib?

Mitchell Coastal vs. Aleut
I have both and I think there are similarities. The Coastal has wider and shorter blades though, and is symmetrical on both sides. With mine, it seems to ask for just a bit of a cant or it flutters a bit. Mine has more useful blade area than a 3-1/4" wide shouldered GP of the same overall length. It is decidedly more powerful and useful for quick acceleration or for correction strokes in bumpy conditions - the wide hand grip position and wider blades are key there. But the shaft is not indexed - mine is round and I wish it was oval …



With the Aleut you have the option of using either side and they seem to offer slightly different feel (at least on the one I carved). On mine, when used as the power side, the flat-ish side has a bit more power and feels more efficient in use. Just a firmer feel in the water. The ribbed side, when used as power side, seems to have a softer feel in the water and I think a little less power, but is more stable and not so prickly about canting - flutters less.



I am not sure if the above is entirely due to the ridge or to the offset in the loom though. Probably a combination of the two. Would be interesting to hear from someone who has the opposite offset, e.g. the smooth face is closer to the center line and the ridged face is closer to the outside line of the shaft…



I had a chance to paddle a GP that had such offset loom and it too had notable differences in feel between using the two sides even though the blades were symmetrical.



I have selected a “favorite” side on my Aleut yet. In flat conditions I seem to prefer the flat side as the power side. But the ribbed side seems better suited for rough water where it offers me more stability through the forward stroke.



I also like the wider loom on the Aleut for my use. Mine is very skinny and flexible Aleut so probably not the same as everyone esles - mine has a lot less power than a 3-1/4 GP of similar length. But is extremely easy and a pleasure to use at a relaxed pace. Still works well in high winds too - the skinny blades offer less windage and there is still enough power in the water to move. Rolling does not seem to be a problem due to the ridge - but mine is relatively low compared to what I’ve seen in other’s designs…

Mitchell Coastal
In a way yes,

The Mitchell Coastal is interesting in that the widest width of the blade looks to be about 10" or so down from the tip. Considering that the very end of a paddle is at the end of the arc of swing, and the tip travels the fastest through the paddling arc, then the far tip has the greatest catch. The Mitchell Coastal appears to disregards this. I made a paddle, in a way similar to this years ago and did not find it to my personal liking because it appeared to lack in as strong as a catch as I expected. Now I 'm not saying there is anything wrong with the Mitchell Coastal paddle design. Most likely the error was with me in not exploring other capabilities of this design.

Not really
If I remember correctly, he started the thread and it was a very thorough on-the-water analysis of the aleutian paddle. He gave numbers using both faces to see the difference. Once again, if I remember correctly, I think that one of the faces worked better at higher speeds, but it’s been a long time since I’ve seen his thread.