I was looking at race photos from the Kanaku Ikaika race (almost all Pueo's??) and I was wondering why the ama on the Pueo looks so straight (flat?) with very little upward curve? Also the iakos look very straight also. When I looked at the Kamanu Composites website, I thought the ama on their website looked a little different than the ones in the race but can't be sure. Can someone comment?
Submitted by catdailey on Sun, 01/18/2009 - 4:44am
Hi Cat,
this is the new ama designed by Keizo. You are right!!!, looks very straight, flat and with very little upward curve. I asked to Luke from Kamanu Composite to build a canoe for me with the older ama, but he said that the Pueo is only available with the new ama.
But one thing is for sure, all the Pueo owners are very happy with the new ama. So maybe we must focus on the performance and not how it's looks.
For me the older ama looks and match much more better with the Pueo design.
Just my opinion.
#1 Sun, 01/18/2009 - 6:13am
Keizo designed it. Supposedly the design was inspired by the shape of a Tahitian va'a. It makes sense to me, less drag than the puffier "surf" amas that have been popular lately.
#2 Sun, 01/18/2009 - 6:16am
Harry:
Yes! That's the design that I remembered from when it first was announced. And Jim, please pardon my ignorance here as I know very little about boats ;< ... if the ama is flatter, wouldn't more ama surface area be in the water at all times, creating more drag than an ama with a bigger curve?
#3 Sun, 01/18/2009 - 7:34am
Hey cat...
Just because the Ama has a longer waterline it does not mean the surface area is greater or the Ama has more drag..Think of it like the boat where the bow line is sharp with an edge that cuts the water line in the first half. Drag is not just about surface area alone...I think Keizo followed a good path here looking at a shape that is efficient with low drag that cuts through the water. Keeping it low also would likely help when its windy.
I have the old Ama on my Kaimana, but it can be a bit 'slappy' at times. I'd love to run it with this new Pueo Ama to see the difference.
Cheers...
#4 Sun, 01/18/2009 - 8:32am
From what I've heard, the ama is recieving very mixed reviews
#5 Sun, 01/18/2009 - 8:46am
Pittbrah:
I think I understand what you mean :> It's a shame that there isn't more scientific testing when it comes to boats. My background is cycling where everything (and I mean EVERYTHING) is wind-tunneled to death. They can tell you how to route a teeny tiny cable, what kind of front brake caliper, what shape tubes, whether to carry a water bottle, down to even whether or not to wear gloves or shoe covers or zip up your skinsuit to reduce drag for every kind of condition (not even getting into swift skin type clothing ;>). Some of the boat posts that I read seem fuzzy in their approach to what exactly makes boat A faster than boat B. It would seem to me that there are huge variables in boat design, some of which would have a significant impact on drag just like bicycles: fore-aft weight distribution and relation to ama placement, hull shape, waterline, weight, stiffness, etc, etc! I'd love to read some actual studies,,, maybe they are out there and I just haven't found them yet...
#6 Sun, 01/18/2009 - 9:07am
Mixed reviews perhaps, but outstanding results in the races, That doesn't necessarily mean anything, though, aside from the fact that a lot of good paddlers have that boat.
#7 Sun, 01/18/2009 - 9:12am
I love the canoe design and the workmanship. I have full respect for everyone who makes canoes and puts the serious time into creating canoes or anything for that matter. So we are just talking about the ama design here. As a hapa haole boy here, it just looks like its got too much Cali. in it. So more oriented for flat water. Out
#8 Sun, 01/18/2009 - 9:54am
I'm not a boat designer and I deal very little with drag as we're discussing here, but I have been studying graduate level fluid mechanics for seven years so I know a few things on the technical side.
My understanding is that the drag on a hull is for the most part due to wave drag, not surface friction drag. So, regardless of the surface area of the old and new amas, if Keizo's new ama produces less wave drag it will have less overall drag. This is why people spend a lot of time working on a low drag shape.
There is a huge amount of scientific testing in boat design, but it generally follows the money to fund it, which means shipping, yacht racing, and other higher profile vessels, or those we don't know about like military applications.
I discussed a little in the other pueo thread about the cost of building a testing facility (it's expensive). Far easier and more flexible is a computational approach that numerically solves the appropriate equations, of which I know there are several commercial codes available and probably at least a few open source (i.e. free for non-commercial use) options.
If you want to learn more, just pick up any introductory fluid mechanics text (I like both White and Kundu) or just read up on Wikipedia or any other of websites.
#9 Sun, 01/18/2009 - 11:46am
sorry, double post
#10 Sun, 01/18/2009 - 11:47am
Ama and OC1 fall under VSV = very slender vessels.
http://www.cyberiad.net/library/rowing/misbond/misres.htm
a rather complex article; the wave drag contribution depends on the length and on the speed of a vessel for a given displacement.
For our design speeds, surface area is the main contributor to drag ( ~ 90 % )
#11 Sun, 01/18/2009 - 2:59pm
I love the new ama. I found that most of the amas that swoop up tend to bog in the surf. The run great in flat water but once a wave hits it from the side it grabs the ama and sucks it down. With the new ama I find it happens alot less.
#12 Sun, 01/18/2009 - 8:20pm
I stand corrected. I think some of the complexity of that article is due to the fact they did a crappy job labeling their axes. If anyone is interested they actually have a few reports probably more relevant to OC-1 design here. Seems like there simulations do a fairly good job when compared to measurements.
#13 Mon, 01/19/2009 - 4:00pm
Gee after watching Karel up close for a couple of hours and playing back the footage over and over, if most people concentrated on developing their surfing skills to a higher level, the perceived performance between different OC1's would pail in significance.
I've discovered, i have a lot to learn. I kid you not.
Cheers Rambo
#14 Mon, 01/19/2009 - 5:18pm
rambo, i come to the same realization 99.9% of the time. the rest of the time i'm paddling by myself.
#15 Mon, 01/19/2009 - 7:54pm
Yo Ramboni,
when you say "if most people concentrated on developing their surfing skills to a higher level, the perceived performance between different OC1’s would pail in significance." you mean it would pail in significance to skill between paddlers?
If that is what you're saying, I agree, however, I also think that to develop surfing skills you need to understand the wa'a you are riding, if you cant, then maybe find a boat you can, or if there is a limitation or something you cannot overcome, a boat, paddle or seat of another color might give you the edge.
Same could be said for technique. If you watch Jr you will know that his technique does not fit the scientific breakdown of what good technique is supposed to look like. So what Im saying is, its all relative, you need to increase your skill, upgrade your boat, have the right paddle, train you ass off, improve technique... list goes on. At any time of your development the focus will change and you will improve.
With that being said, if we all would spend more time understanding water I think you will make the biggest improvement. I mean that in the most general terms.
Like Bruce Lee said "Empty your mind, be formless. Shapeless, like water. If you put water into a cup, it becomes the cup. You put water into a bottle and it becomes the bottle. You put it in a teapot it becomes the teapot. Now, water can flow or it can crash. Be water my friend."
...and go get yourself a Scorpius!
#16 Mon, 01/19/2009 - 8:15pm
eckhart, I don't think typical oc1 ama's always fall under 'very slender vessels' or thin ship theory. I don't have data to confirm this, but based on my experience with different ama's and purely off observation -- wave drag does become a larger contributor when the loading or displacement on the typical ama is increased.
The surface area argument is often made, but if that's all there was to it, every ama would be a beach ball. In fact, a spherical shape probably would make an amazing ama under the condition that you could keep the loading on it very close to zero -- or light enough that the wave making contribution of drag is insignificant. Unfortunately, it seems most of us are not that skilled.
The displacement on a real ama is so unpredictable depending on the conditions and paddler skill that one has to assume a huge range of possible displacements. Sometimes it's zero. Design loading is about 5 lbs. Then it's reasonable to expect 10-20 lbs with relative frequency and sometimes 20-30+ lb loadings. The Pueo Ama was designed to remain streamlined under all of these conditions. Some performance might actually be lost in the range that viscous drag dominates, i.e. when your ama is super light on the water. Based on paddler feedback, the Pueo Ama seems to differentiate itself in that there is never a sudden drag increase from wave and pressure drag. The goal is to have less drag on average, not just at certain times.
So eckhart, maybe that would be a good one to add to your time trial. Try put a 10 lb weight on different amas in flat water and see how they compare. I would be curious to know. Hopefully you won't just find that I don't know what I'm talking about. :)
Rambo, all surfing skills are important, but you can't discount the boat model. Take a look at the last 3 races on Oahu and look for a guy named Justin Watts. Pa'a race: Arcturas, Kanaka Ikaika 1: Viper, Kanaka Ikaika 2: Hurricane. Only one example, but I think it says a lot.
Also, catdailey, I agree and wish there was more data taken and available. One day.
#17 Mon, 01/19/2009 - 8:15pm
Wow ! At last ! A paddler who knows Bruce Lee !
Joe you're my brother from now !
#18 Mon, 01/19/2009 - 8:48pm
i now see while Keizo is such a small dude. his brain has seized control of his body's systems and diverted the flow of nutrients to itself. it is therefor much bigger and more productive while his body suffers somewhat. if you have ever seen Keizo eat, then you know what im talking about. he eats about 2 times his body weight daily.
#19 Mon, 01/19/2009 - 8:54pm
OK let me put it another way.
For the Average paddler, Swapping from a Scorpius to a Zephyr to a Pueo or any other late model Hawaiian designed OC1, will not make as much difference as improving your surfing or water reading skills in a downwind run.
At the pointy end of the field, the difference is not so great, as the skills between these paddlers are close and any edge is a bonus.
However, how many of you stick with your mate upwind or in flat, but as soon as you turn the downwind buoy your surfing skilled mate beats you home by 10 mins.
I doubt changing canoes will make up that difference.
Keizo, they are pretty radically different canoes Viper / Hurricane, so of course there will be larger differences there, comfort can be a big killer of performance.
My point was, and it's just my opinion, improving surfing skills will pay off more for most of us.
Cheers Rambo
#20 Mon, 01/19/2009 - 9:28pm
Hey Keizo, you may be right about the ama not being a very slender vessel; I think the definition depends on the length to beam ratio.
I am not sure how long the waterline of an ama generally is, the beam is about 5 - 6" right ? Do you have some numbers about the wave drag ? The bottom of the ama is quite flat ( transverse ), why did you decide against a more round section, if you don't mind me asking ?
An ama with gradual changes is a good idea. Once I find a boat we can do some testing.
Like Justin, I did the three races on three different boats; the first race I was more than 6 minutes ahead, the second about a minute behind, the third about a minute in front of a paddler that usually has about the same results.
The last race went well on a Hurricane - I lost about a minute because I couldn't get in at Kaimana because of the break - I had run over the reef there previously, so I was especially careful. The Hurricane did well as expected. Just at Black Point where it got choppier, it ran less well - you can expect that with my weight and that design, too.
The second race was on a Zephyr. It was a flat water race and I had planned to take the Hurricane, but couldn't. It was not the ideal choice. I probably should have placed 1 or 2 lbs weight on the front deck to balance my trim a bit that day. I think that would make a difference for my height.
The first race was on a demo Pueo. I hulied; I dare to say that the ama set up was responsible for that. Other than that, the boat ran very well. This is for my weight and my height.
Going out to the first buoy the small backwash from the rocks bothered me and made the boat feel unstable, backwash from back left unto the ama.
After the second buoy into the wind the wind blew up the ama twice, once I could balance it, the other time I couldn't and just tipped over
- the reason was mainly that you have to brace a little further back on the Pueo than I am used to.
For Rambo - the impressions that I have gotten form the Pueo - one week test paddle - is just the opposite of what you suggest - it makes the average paddler a better surfer; suddenly you get stuff that you did not get before.
I did a morning run with friends and the spontaneous comment was - "the best you have surfed in your entire life".
The Zephyr reaches higher speeds downwind, is extremely comfortable and will be difficult to beat in larger waves.
Your comment about surfing skills is of course correct.
All this for my weight/height and may be entirely different for other paddlers.
#21 Mon, 01/19/2009 - 9:49pm
Ecky, you have to discount the fact that two of the canoes were unfamiliar to you. If you continued to paddle all 3 over a period of time the differences would be smaller. If all 3 canoes were "tailored" to suit you, the differences would be even smaller.
Cheers Rambo.
#22 Mon, 01/19/2009 - 10:00pm
One thing that the top paddlers all have in common, is that their Ama spends less time in contact with the water than the rest of us. There's a big speed gain and directional control available there if you develop the skill. Your paddle becomes primary stability, your Ama secondary, so you beat the design.
Cheers Rambo
#23 Mon, 01/19/2009 - 10:04pm
Yes Rambo, I agree, your points are well taken. When you step on a Hurricane in flat water, you will say - 'nice release' and you will enjoy the glide. When you changed to your Peggy, you said less effort to get going in the following sea.
With the Pueo, you may say, 'I told you, that I know how to surf' - a little bit like the 'Hurricane' feeling, but for medium waves.
Here is another example, and again just my very own experience: usually on a downwind run when I get behind, I stay behind - not much I can do. Downwind on a Pueo, I am very much able to close larger gaps, and not at a huge expense, but by surfing.
I personally am not sold on the ama yet. There were days when I liked it quite a bit, other days when I didn't. I didn't have enough time to make up my mind about it.
Yep, I saw Jr once on the crest of a wave with almost no speed, working hard, the ama was up in the air the entire time until he dropped in, very impressive.
#24 Mon, 01/19/2009 - 10:09pm
I'll take your word for it Ecky, as i haven't paddled a Pueo so i can't have an opinion.
It is funny though how you always feel faster in a new set of Nike runners.
Cheers Rambo
#25 Mon, 01/19/2009 - 10:09pm
Well think about it - didn't you think that you were better off with your Peggy because you needed less energy to drop in ? And you are faster with new Nike shoes, as much as I am faster with new Adidas runners :).
I wouldn't want to say one boat is better than the other; because I don't know. But I can say that for my level of skill, my weight/height and the conditions I paddle in, one boat works better than the other.
#26 Mon, 01/19/2009 - 10:18pm
Yep, i'm no different to anyone else. At the end of the day we all purchase on emotion, whether that be cars, houses or canoes. If it feels good you buy it.
Hopeless creatures aren't we and the sellers know it... hahaha
Rambo
PS I'm just upping a little video treat for you guys, be about 10mins. I'll post it here.
#27 Mon, 01/19/2009 - 10:45pm
So true Rambo. I bought a boat that is probably too big for me but it felt good and literally feels better everytime I paddle it and its been about 9 months so thats saying alot. I know there may be other canoes more suitable out there but I have logged alot of hours on it and just keep on cracking and it feels like its paying off by concentrating on what I have.
Ultimately if you win or just do well for your level nobody sais "He or she did well because they were on a...". Just as when you lose or finish poorly they dont say its the fault of the boat. It always comes back to the motor.
#28 Mon, 01/19/2009 - 10:53pm
Nice conclusion to the thread Rambo!
There have been a number of breakthrough's in oc1, I hope they keep on coming. Mahalo to Kai, Karel and Keizo guys for putting it down.
@Hiro: right on my friend! Paddling is a lot like martial arts, no? One does not accumulate but eliminate. In building a statue, a sculptor doesn't keep adding clay to his subject, he keeps chiseling away until the truth of the creation is revealed.
#29 Mon, 01/19/2009 - 11:34pm
Hey Ecky, while i'm waiting for that upload, about the Peggie and what i said about wanting to drop in easier.
I discovered that was true to a point because of the more forward cockpit position, but also i realized that my timing was off and i was paddling hard a couple of strokes too early, and i should not be in the position where i have to drop in that often if i link up better, so i learned a lot from that.
OK the vid is ready.
oops had second thoughts this thread is headed Pueo so to be respectful to all i best post the vid in it's own thread.
Cheers Rambo
#30 Mon, 01/19/2009 - 11:38pm
joe,
I had the chance to speak with Gerard Teiva (Shel's coach) last month. He speaks like a sensei. When talking about paddling he uses words like flow and circulation of energy in your body, projection of mind, offensive or defensive strokes... It was mind opening.
Maybe we will practice Padoringu-Do in the future.
#31 Mon, 01/19/2009 - 11:56pm
can you expand on offensive and defensive strokes?
#32 Mon, 01/19/2009 - 11:58pm
That's the strokes you would use to go fast or the ones you would use to take some time to breath...
The naming is important in that calling things with a different name set your mind on a different path... A "fast stroke" is... well... just fast. An "offensive stroke" is set to break your opponent...
#33 Tue, 01/20/2009 - 12:02am
hiro & joe,
nice analogies. it is a great way to look at things. read the book of five rings. you can associate what is written in it and apply it to anything in life.
#34 Tue, 01/20/2009 - 8:08am
@Hiro; what a great strategy. I have learned in my paddling that it is about adapting to the water, opponent or physical condition, so changing rhythms throughout makes sense. Thanks for sharing.
@nalu; 5 rings; one of my favs. Try sword of no sword, another good one. Im sure you're familiar with Hagakure, if not, the applications to paddling are jaw dropping.
#35 Tue, 01/20/2009 - 8:36am
Thanks to everyone who contributed to this thread... this one's a keeper ;>
#36 Tue, 01/20/2009 - 11:29am
yes.
Thanks Hiro . It sounds like a whole nother level. Cool. I took Tie Chi for a year and still use it today. it helps alot. I also am a big Bruce Lee fan , so much so I named My oldest daughter, her second name Lee after him.
#37 Tue, 01/20/2009 - 4:10pm
everyone should read the Book of Five Rings.
That's something we forget too often : our limits can be pushed further than what we usualy believe possible.
#38 Tue, 01/20/2009 - 8:37pm
Kiezo talks about wave-making resistance changing with ama loading. Rocker, then, gives the ama variable waterline length therefore variable length-to-beam ratio & surface area/skin friction and therefore variable Froude number. This makes it much more complex than the quoted study of rowing sculls.
Any thoughts anyone?
#39 Wed, 01/21/2009 - 10:11pm
Hiro said: "everyone should read the Book of Five Rings.
That’s something we forget too often : our limits can be pushed further than what we usualy believe possible.
Be water, my friend.
http://tuaruavaa.blogspot.com/"
Hiro, I would prefer Lord of the Rings, can you guess which Hobbit reminds me of Rambo!
"I am the ring bearer, the responsibility is mine and mine alone"
#40 Fri, 02/13/2009 - 12:39am
As a well known Flight Steward once said ..... There's no compensation for "ring" damage !!!!
Rambo
#41 Fri, 02/13/2009 - 12:53am
Somehow I missed this thread, so thanks Clarkie and Rambo for digging it up, for I'd like to add a few comments:
#42 Fri, 02/13/2009 - 7:21am
Koacanoe, the side of your hull has more rocker than the bottom and can be used to keep the nose up and assist in turning the canoe better.
In the ocean, your wake is insignificant compared to the waves and wind so not sure bow would effect much.
Cheers Rambo
#43 Fri, 02/13/2009 - 12:55pm
koacanoe - great reminder.
Closest ama position is not necessarily the best way to ride the bow wake.
You have to decide at what speed you want to ride that wake as it changes with speed.
#44 Fri, 02/13/2009 - 11:26am
Eckhart: The hull rides the bow wake and the ama rides the hull wake.
Rambo: I would think there be more wetted surface area, rather than rocker when on its side? Also, them unlimited long boat skis, such as the S. African Fenn, were designed to take advantage of the bow wake produced.
#45 Fri, 02/13/2009 - 8:45pm
Koa it may be a question of wording; google for 'bow wake' and check the image results - that's the wake that I mean. This is how I understand it:
When you are faster the bow wake will be higher , spread more and hit the ama earlier;
that's why you may have to adjust the distance ama/hull according to what you want to happen.
I don't think that a boat 'rides' its own wake. A wake is formed by the water displaced by the volume of the boat. Depending on the length of the boat and the speed of the boat wakes have a certain frequency.
The higher the speed the further the second wave moves back.
At 'hull speed' the second wave is at the stern and the boat sits between those two waves, one at the bow and one at the stern.
Lower speed - more than two waves along the hull; higher - stern wave moves even further back and boat seems to 'climb' the bow wave.
#46 Fri, 02/13/2009 - 11:54pm
A canoe will ride in the hollow created by the bow and the stern wave, but as i said before, the ocean waves will mess with everything.
Ramboscie
#47 Fri, 02/13/2009 - 10:26pm
Rambo: Go check out Dyson on forked bows and them Greenland Eskimos paddling in big cold water and maintaining 10 knots.
Eckhardt: Of course it's words and thanks for setting me straight. I appreciate your explanation, for I'm always thinking in terms of counteracting (opposite) waves: wonder if a bulb or fork bow would work?
#48 Sun, 02/15/2009 - 12:19am
koacanoe - they say that bulbous bows work but only at much higher speeds than OC 1.
Fork - no idea. The Aleutian kayak has a forked bow, looks great and gets very good reviews.
#49 Sun, 02/15/2009 - 4:12pm
with or without a rudder ? a rudder would slow you a bit.
#50 Sun, 02/15/2009 - 7:28pm
I used to sit around campfires listening to stories about canoes that would ride their own wash. Mythical vessels made by the gods!@#$
#51 Mon, 02/16/2009 - 12:13am