Does chime affect speed? For instance, if I had 2 identical boats but 1 had a soft chime and 1 a hard chime, would one be faster than the other?
I Don’t Know About Speed
– Last Updated: Aug-12-12 11:19 AM EST –
but I think the word is chine. With an n. Why don't you delete and start over?
Not chine
– Last Updated: Aug-12-12 11:34 AM EST –
If a hull has a lot of rocker with a hard chine against a soft-chined boat with much less rockered hull, the soft-chined boat will likely be faster all other things being equal. A fine ended boat may be faster than one with fatter ends. A plumb bow boat of the same length as one without a plumb bow could be faster. A boat that is quite skinny compared to its length will likely be faster than one that is wider compared to its length - except for time lost recovering from a capsize if it is really skinny. :-)
What is the real question here - are you trying to compare boats? Hull speed is about multiple factors, which boat designers are quite good at discussing and the rest of us should probably not try to get too fancy talking about.
yes
– Last Updated: Aug-12-12 12:06 PM EST –
Excluding other factors, a rounded cross-section hull will be more efficient than any other shape. It has less wetted surface area. Can't quote you chapter and verse, but, do recall, for example, John Lockwood of Pygmy boats, explaining that a multi-chine hull was about 3% more efficient than a single chine hull. The multi-chine is closer in shape to a rounded hull. Similarly, a soft chine is closer to a rounded hull than a hard chine.
DOH!
chiNe. Sorry about that…should have seen it coming. 
LOL.
Best chuckle I had all morning.
Sorry, couldn’t resist.
This is what I’m asking I guess.
I recently got a chance to paddle an Eddyline Night Hawk 16 with a soft chine. Very nice kayak and much faster than my rec boat. Somewhere down the line I was thinking about getting an Eddyline Fathom which is basically the same boat but it has a hard chine. I was wondering if a hard chine slows the boat any.
the problem is
Those 2 boats have other hull differences, so, if there’s a difference in efficiency, you can’t really hang it on the chine difference. My explanation was “excluding other factors.” But, here, you have other factors.
efficiency
I don’t get this whole efficiency discussion. It comes up time and again with folks obsessing over efficiency but with the boats that they are talking about it won’t make a lick of difference. Even in the theoretical context, it will be almost meaningless for 99% of paddlers. Unless you’re racing, the chines on your boat won’t add up to any appreciable difference in speed, especially if you have bad technique. Trust me, Greg Barton will still beat the tar out of you if you’re a soft chine boat and he’s in a hard chine boat.
Chines will change the feel of your boat’s handling and can dramatically increase your secondary stability while making newbies a bit nervous about feeling “stable”. It can also make deeply carved turns drag a bit and will force better edge control.
Additionally, I agree with Celia regarding the wetted length in the water due to rocker.
Race boats are 18’ and longer, generally, with no rocker and no chine. They don’t have any similarities with the boats that your considering other than they float as well.
The Chine Effect
The fastest deep water paddlecraft, ICF Sprint boats have soft chines and long recoveries, with copious rocker fore and aft.
Some shallow water racers, USCA Cruiser type craft, have hard chines aft to keep waves away from the hull. Look at the GRB/ Newman Design website.
Hard chines increase initial stability by placing volume wider but hard chines hulls heel unpredictably which can pitch one into the drink suddenly.
Who said basically the same boat?
The Nighthawk is a few inches shorter with the same max width, but more importantly it is one of Eddyline’s older boats and the Fathom is a good bit newer. It sounds like the Fathom may have at least more rocker, per the description, and being newer there are probably other differences that can’t be easily seen in a photo on the web. You usually have to see these boats in person or talk to a very well-informed rep to find out the differences between hulls.
Is that where this information is coming from, or is a best guess based on the web images and (very basic) specs?
(Canoe seem to still post better specs to make this kind of assessment.)
Chines - history and racing
Historically, chines appeared on paddle crafts because they were created by the construction technique when using skin over frame, and by some all-wood construction techniques.
Chines reappeared in the composite era mainly, I think, as quasi-historical reproduction (“retro”) features. Some paddlers may like how chines affect turning and edging, but I’m not sure there is any claim that hard chines improve speed.
There may be exceptions, but I don’t think racing canoes in any paddling discipline – marathon, sprint, downriver, ocean – single blade or double blade – feature hard chines. If hard chines added speed, racers would have adopted them.
I visualize turbulence forming along a sharp longitudinal edge and adding drag for a paddle boat displacement hull.
chimes might affect sound
Humph!
I’ve got a Greg Barton signature paddle.
neato!
that alone may make you go faster!
Nighthawk vs Fathom
My subjective experience is that a soft chine feels a bit smoother to paddle because you don’t feel the hard edge no matter how you lean it—it transitions smoothly throughout the lean and back again. But it’s an inconsequential difference to me personally. I don’t notice any “not smooth” paddling with a hard chine.
If you’re choosing between the Nighthawk and the Fathom, I don’t think the speed of one chine vs the other is really a factor. The Fathom is Eddyline’s updated hull design, which is carefully thought out to balance tracking, stability, and maneuverability. It’s a good hull.
If you get a chance to demo the two back to back I’d be interested in hearing what you observe.
That’s right
The Greg Barton stickers help, too.
I knew you’d chime in
Wetted surface
– Last Updated: Aug-13-12 6:57 AM EST –
If the wetted surface is the same, both hard chine and soft chine would be the same speed. This was asked on the Guillemot building site and Nick Shade posted a computer graph of the same boat with hard and soft chine - BUT - the same wetted surface. The computer model was worked from wetted surface backwards.
The caveat to this is however: converting a boat from a soft chine to a hard chine usually creates more wetted surface and therefore the hard chine boat would be slower.
The fastest hull is always a half circle shape but very tippy and almost impossible to paddle.