Mixing Up Attributes
two boats of equal volume: the one with more “V” or flare from the keel line will have more secondary stability than the a flat bottom boat. The flat bottom boat will feel so stable on flat water than you can stand up on it whereas to do so with a more “V” shape boat will result in a flip. The “V” shape boat however will handle uneven surfaces better, ie. waves, because it’s secondary stability kicks in.
The shape of the chine has nothing little impact on the primary vs secondary stabilty. There is a noticeable hinge effect when a hard chine boat is leaned past as it’s secondary stability whereas the rounded chine doesn’t have the hinge effect Rather, it there is feel of progressive resistance to a point at which the secondary stability is overcomed. Yes, hard chine will carve better on a leaned turned but as someone also pointed out, the shape of the hull from a down down view also affects the turning.
sing
hull shape has nothing to do with
stability?
I think you may just be arguing for the sake of arguement.
Hull shape has a lot to do with stability.
ever try paddling a surfski? Compare that to a flat bottomed planing hulled ww kayak and I think you’ll find some differences.
Do you paddle at all, or do you just troll?
Best to study that web page
that has been posted earlier. The underwater shape is important as it effects how the center of bouyancy and the center of gravity align with each other while the boat is heeling. It’s all in those curves.
Mike
Two kayaks to test against each other
Anas Acuta and Pintail - the Pintail is basically a soft chine version of the Anas - with a half inch added in the beam.
Go Paddling!
Geez… the weather must be pretty awful out there. I’m on line briefly to catch up on work before heading out to paddle.
A hull’s profile and form is more complex than any of us who are not nautical engineers or boat designers will likely comprehend. It is best to simply tryout any boats avaialble whose performance targets are within your desires.
LOL
Well…
I was responding to the statement that “STABILITY IS A FUNCTION OF VOLUME, NOT HULL DESIGN”. If that were true, then all shapes of equal volume would be equally stable. And naval architecture would be a much simpler profession…
It’s only a troll if…
you go a long while with no bites. That rarely happens here.
fair enough
you definitely got responses…
the wider boat turning quicker bit
makes sense, i can visualize that. i suspect the overall character of the curves as well, size, length, depth, shape, plays a role. the more the boat has rocker as well as S shaped curves lending the boat a ‘belly’ type appearance the more of the boat gets out of the water on a strong lean where it can pivot on that gut. like in my prospector canoes, or for that matter, my Formula Cadence kayak which is a gutty boat.
go paddling, why yes, but i for one have enjoyed this thread.
Waterline changes with lean…
...so over and underwater sections change. Center of Buoyancy moves, etc.
Link again:
http://www.guillemot-kayaks.com/Design/StabilityArticle.html
I Never Understood…
why someone would jump into a thread and then tell everyone to "go paddle." The assumption I have is that folks do paddle more or less. They're here to discuss whatever is on their mind when they are not paddling, and others are obviously willing to discuss by responding. I mean, really, how many folks are paddling 24/7? And, then you have to think, If someone can jump in and post, "Go paddle", how come they are not out there doing what they proposed. If they were, they wouldn't be here to post such a prescription...
Ah, the little mysteries... :)
BTW, Wilson, this thread is not really much different than the many threads you have participated in, comparing one "Brit" boat to another. I have read many of those discussions, though I may choose not to participate, and often they focus on the attributes of the hull design and how these translate into performance as experienced by the different Brit boat owners. This thread really isn't much different, except the responses on this thread aren't overly focused on a specific boat vs another as do some of the discussion you've been in, e.g. Aquanaut vs. Quest, or a Capella vs. Avocet, etc. Your discussions, nevertheless, are usually about hull attributes as these are here. However, the Brit boat discussions do occaisionally drift into the "why a day hatch is great" type of endorsement. I'm just tweaking ya. :)
sing
There’s an ancient proverb…
...that goes something like:
"It's better to remain silent and be thought an idiot, than to speak and remove all doubt."
To wit: "hull shaped has to do with turning, tracking and other performance factors but nothing to do with stability"
Once again, you've stated a strong opinion on a subject that you know nothing about and obviously don't understand. How many times are you going to have to get verbally "slapped up aside the head" before it sinks in?
If you don't understand something, try asking a question rather than posting an uninformed opinion. You'll get better answers and less criticism.
Fair enough
I apologize profusely for my earlier “Go paddle” comment. Really was not intended to be serious, rather a reaction to being burned out a bit by techno talk. I believe that people place far more emphasis on gear than skill. I recognize that a lot of you are serious paddlers and just very enthusiastic about all aspects of the sport. I get that…