Speed Rating of Kayaks

On 9-May-2005, "W. Watson" wrote:

> Does anyone rate the cruising speed of various kayaks?

Usually drag versus speed. Sea Kayaker magazine publishes this info with
their reviews.

> For example, what's the
> speed difference between a kevlar, fiberglass, carbon, polyurethane, teak, and
> others for the same hull design?

Negligible if new and properly made. Once they get scratched up, the
plastic boats tend to slow more than others due to the way scratches
produce fine hairs that get into the flow. The other materials tend to
scratch by developing gouges in the surface, which slows them down but
not as much as the fuzzy plastic bottoms.

> Is there a common way, standard, to measure the speed of a kayak? Wind tunnel?

Towing tank. It's expensive so most reviews use standard drag prediction
formula. Sea kayaker uses both Taylor series (by Broze) and KAPER (by
Winters) and they produce similar results.

Mike
 >> Stay informed about: Speed Rating of Kayaks 

The math lesson would likely prove problematic in practice with boats
of different hull design. Smooth entry and clean flow vs. abrupt
unclean bending of waves.
( Sealution XL , VS say Nordcap ) Similar length and displacement but
the nordcap is a little faster.
Plastic is going to be a little slower than most composite boats
because of fuzzies and oil canning. The boat either has a permanent
bend of undulates with the water slowing it down.
Glass and Kevlar would be so similar as to be difficult to detect in
the water. Now they get to and from the water 10 Lbs faster.
These are my opinions and are based on the persuit of laziness while
paddling.
Alex
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On 9-May-2005, Ted Marz wrote:

> Seems to me I stated that beyond the wetted water line issue, it was a
> power / drag issue.

No, you said there's a theoretical maximum speed. There isn't.

> 2) A light hull - because you'll have less weight that you have to
> push, making your "work" (in physics terms) more efficient.

For acceleration, yes, but for maintaining speed, you'd have a hard
time detecting the difference.

Mike
 >> Stay informed about: Speed Rating of Kayaks 

Michael Daly wrote:

> On 9-May-2005, Ted Marz wrote:
>
> > Seems to me I stated that beyond the wetted water line issue, it was a
> > power / drag issue.
>
> No, you said there's a theoretical maximum speed. There isn't.

Yes there is. It's 3 x 10^10 m/sec, also known as 'c', the speed of light in
a vaccuum!

Have we geeked out enough yet?

John Kuthe...
 >> Stay informed about: Speed Rating of Kayaks 

"John Kuthe" wrote in message
> Michael Daly wrote:
>
> > On 9-May-2005, Ted Marz wrote:
> >
> > > Seems to me I stated that beyond the wetted water line issue, it was a
> > > power / drag issue.
> >
> > No, you said there's a theoretical maximum speed. There isn't.
>
> Yes there is. It's 3 x 10^10 m/sec, also known as 'c', the speed of light in
> a vaccuum!
>
> Have we geeked out enough yet?
>

No.

My physics text says it's 3 x 10^8. Your light moves 100 times faster than mine! I feel slow.

But if you really want to geek out, it's actually 299792458 m/s.



-Paul
 >> Stay informed about: Speed Rating of Kayaks 

On Wed, 11 May 2005 19:37:38 GMT, "Paul Skoczylas"
wrote:

>"John Kuthe" wrote in message
>> Michael Daly wrote:
>>
>> > On 9-May-2005, Ted Marz wrote:
>> >
>> > > Seems to me I stated that beyond the wetted water line issue, it was a
>> > > power / drag issue.
>> >
>> > No, you said there's a theoretical maximum speed. There isn't.
>>
>> Yes there is. It's 3 x 10^10 m/sec, also known as 'c', the speed of light in
>> a vaccuum!
>>
>> Have we geeked out enough yet?
>>
>
>No.
>
>My physics text says it's 3 x 10^8. Your light moves 100 times faster than mine! I feel slow.
>
>But if you really want to geek out, it's actually 299792458 m/s.
>
>
>
>-Paul
>
186282 Miles per second isn't just a good idea, it's the law!
 >> Stay informed about: Speed Rating of Kayaks 

On Mon, 09 May 2005 15:30:21 GMT, "W. Watson"
wrote:

>Does anyone rate the cruising speed of various kayaks? For example, what's the
>speed difference between a kevlar, fiberglass, carbon, polyurethane, teak, and
>others for the same hull design? Is there a common way, standard, to measure the
>speed of a kayak? Wind tunnel?

For kayaks of the same design, the hull speed will be virtually the
same. Sllight differences may occur due to smoothness of the hull,
flexibility and weight. A study was done a number of years ago
comparing smooth versus badly roughed up hulls. The surface condition
differences were lost in the hull shape differences.

The standard way to measure resistance vs speed (speed alone is not a
valid measure for kayaks) is to use a towing tank such as those used
for ship design. Since this is very expensive, some very good
approximations have been developed that are calculated from the hull
section shapes.

See Sea Kayaker magazine boat tests for a good ongoing display the of
these calculations.
 >> Stay informed about: Speed Rating of Kayaks 

Paul Skoczylas wrote:

> "John Kuthe" wrote in message
> > Michael Daly wrote:
> >
> > > On 9-May-2005, Ted Marz wrote:
> > >
> > > > Seems to me I stated that beyond the wetted water line issue, it was a
> > > > power / drag issue.
> > >
> > > No, you said there's a theoretical maximum speed. There isn't.
> >
> > Yes there is. It's 3 x 10^10 m/sec, also known as 'c', the speed of light in
> > a vaccuum!
> >
> > Have we geeked out enough yet?
> >
>
> No.
>
> My physics text says it's 3 x 10^8. Your light moves 100 times faster than mine! I feel slow.
>
> But if you really want to geek out, it's actually 299792458 m/s.

I scwooed up! It was 3x10^10 cm/sec! Which I had typed, but then miscorrected to m/sec! Oops!

I fail my geek test! But I still have Pi memorized to "3.1415926535...", and probablu always will!


John Kuthe...
 >> Stay informed about: Speed Rating of Kayaks 

In article , W.
Watson wrote:

> Does anyone rate the cruising speed of various kayaks? For example, what's
> the
> speed difference between a kevlar, fiberglass, carbon, polyurethane, teak,
> and
> others for the same hull design?


Damned little. Water speed has mostly to do with waterline length.
Kayak composition affects that minimally. Lightweight construction has
more to do with ease of getting kayaks on and off your car, and
portaging than their performance in the water.
 >> Stay informed about: Speed Rating of Kayaks