Width vs speed...how much?

So for people who "know how to paddle well" how much tradeoff in speed do you see between the X-Factor, T140/160(i), the Prowler Big Game and the P15 Trident?

Are you seeing 2-3%?  10%?  25%?  Obviously the 160i will be faster than, say an X-Factor, but how much of a factor (pun intended) is the extra width/design?

Also, for you ocean fishers ... skeg vs rudder vs nothing?  </can_o_worms>

Thanks! 

-Mike

Not sure how accurate this is but I found an article on estimating sprint speeds based on width and length.
http://www.wavelengthmagazine.com/2001/on01howfast.php

They came up with the following formula..

kts = 9.15 - 27.71*(W/L)

This is a really simplistic model.  There are a lot of other differences in hull shape that will effect speed, but this seems good enough to help answer the type of question posted here.

Tarpon 160 specs.. 16' x 28" = 5.1 kts (5.86 mph)
X-factor specs ... 12'6" x 36" = 2.5 kts (2.87 mph)

Brian

If you've got a GPS......put it in the Mode that reads out speed......and try out any design you like.

Within 100 feet of any "effort" the GPS will be reporting speed to you.

If you make a special effort to paddle at the exact same rate & effort, the GPS will deliver comparative information between the boats.

The best answers in the world are the ones you derive yourself.

My own personal cut on rudders is:  They are the POX.

Judd

No 28-inch wide boat ever made......delivers 7.7 mph without a motor.

To get 7.7 mph requires a sit-inside kayak that's 17-feet long, and 21-inches wide.    21-inch-wide boats are all (every one of them) so inherently "tippy" that if in choppy water you close your eyes and put down the paddle....seconds later you will be snatching for that paddle.    In a 21-inch-wide boat in anything but mirror-pond conditions, it's difficult to put down the paddle long enough to sort out the controls on your camera and take a picture.

And.....even in that 21-inch-wide sit-inside kayak....it would take an athletic person putting in an endurance level effort....to do 7.7 mph and keep it up for an hour.

My 23.5-inch wide, 14-foot kayak sit-inside kayak....(23-inches is the width-minimum required for sufficient stability to thread-hooks and do the things that fishermen have to do)....If in my boat I put in the highest endurance-level pace that I can keep for six miles.....I will be doing 5.4 mph.     This same boat paddled at a NICE pace......you know, the kind of pace you would choose to paddle if you had no particular goal and no one was watching....would go at a very lovely 4.4 mph.

For all boats there is a POINT that's often +/- 1-mph right around 4 mph....beyond which....any increase in speed comes at increasingly prohibitive cost.

The magazines lie......
The pundits lie.......
The manufacturers lie.....

But let me tell yah, mah fren, the GPS it don't lie none atall.

Judd

Hey Judd,

Thanks for pointing out my mistake on the Knots to MPH calculations.  Not sure what happened there, but those were way off (I edited my above post to correct them).

By the way, this is a sprint speed calculation.

I'm not saying that this calculation is any better than your GPS method. It's just a heck of a lot easier to do some quick back of the envelope math than round up a GPS and every model to answer moxford's question.

I say, "what's the hurry?"  Get a more stable boat (X-Factor) if you're going to go in the ocean much.  Get a faster boat if you're in a hurry!   

Test paddling is the best "calculation", IMO.

I say, "what's the hurry?"  Get a more stable boat (X-Factor) if you're going to go in the ocean much.  Get a faster boat if you're in a hurry!   

Actually, it's not about being in a hurry, but with "x" energy expenditure a faster boat will require less exertion to move at "n" rate.

On flat water, no wind, no current, sure....what's the hurry?  But when the chop picks up or the gusts come in the more efficient boat will be easier (and, thus, more enjoyable) to paddle before "big exertion" hits.  It's not about top-speed for me, but rather, the inherent efficiency as the environment start degrading.  The bigger boat will become more cumbersome more quickly than the efficient boat.

The numbers above, post-correction, for the T160i being roughly twice as fast as the X-Factor..is impressive, even giving substation %'s for it being a rough calc.

Buying and taking a FF w/GPS or GPS with me on the test paddle is a good one. (I'm a complete newbie, so please excuse me for not thinking of it myself.

-Mike

I think, Mike, that in degrading conditions I'd much rather have a stable boat than a faster one.  The reason being:  in a skinny boat you are in danger of flipping in the bad conditions more than the (inverse) probability that you would be "safer" with a less cumbersome boat in the bad conditions.  Cumbersome as it is, if there are winds and waves and I have to get to port in my X-Factor, or worse, get rescue gear out, I want that extra assurance that I will be staying top-side.

Example:  I've been paddling up the South Fork of the Eel River winter flow with the X, without so much as a hint of a tip in currents that want me to turn around.  In a skinnier boat, like the 160 or 140 I'm sure I could paddle upstream faster, but I'd be much more concerned about flipping.

Example II:  I've spent lots of time on the ocean in whitecaps in the X, but never on a 140 or 160.  I'm pretty confident that I'd be scared shitless on one of those in whitecaps, but I could be wrong...

$.02   

I think, Mike, that in degrading conditions I'd much rather have a stable boat than a faster one.  The reason being:  in a skinny boat you are in danger of flipping in the bad conditions

have to agree with Abking about this one.  As a fat uncoordinated guy in a tarpon 160i, I can say that when things get ugly tippy is bad and the 160 is more tippy than a wider stable boat.  you end up doing a lot of bracing and lose your glide, which seems to be why you are faster in the first place.  you may not dump it, but the security is not there.

You guys rock; thanks for taking the time to respond and help out on this!

My list of boats to test-paddle is shrinking nicely... woohoo!  I'm still having trouble getting over the numbers of the Trident/160i being twice as fast (on paper) as the FnD/BigGame/X-Factor, but ... meh. 

-Mike

I can paddle most yaks in the 3.2 to 3.8 mph range on a steady pace.  Yes, I've had the Prowler 15 up in the mid 7's on a sprint, but not for very long.  And I can sustain a pace in the low 4's, but why do that unless you have to.

Where do the various yaks you've listed fit in this range.

I own a Big Game.  I get 3.2-3.4.
I've owned an XFactor.  I get about 3.5.
I own a P15.  I get 3.6-3.8.
I've owned a Cobra Triple.  I can get 2.8 on it paddling solo.   

All approximates and I'm sure they change depending on my current level of fitness.  But it gives you good relative speeds.

Abking, I was having that very conversation with Zee this weekend.  Take a P15 in a following quartering sea and you need to be careful not to take one in the lap.  I'm going to say that the extra time I spend on boat positioning and bracing under those circumstances is equivalent to what I'd spend on a slower, more stable boat ... this is a very rough guess.

-Allen

Oh ... and for you science geeks wanting to know more about length and its effects on speed.

http://www.inkdrop.net/qajaq/kayaking-science_WCSKS_07.pdf

Everything you ever wanted to know about the science of kayaking  ... AND MORE.

-Allen

Geeze.  I'm sort of good at math and probability theory and such, but you guys can have the pie.  Are we discussing comparing longer narrower more tippy boats with shorter wider more stable boat hulls?

At the risk of appearing stupid, or off subject, and at my own risk;  I've always been fascinated by the various hull shapes of all boats, and the steamlining of cars and all that.  Since the mathematics involved are always far beyond my meager mind, I tend to look at boat hulls intuitively.

For example: Let us compare my squat Hobie Sport to my neighbors' sleek Hobie Revo:  When we go on the river together, we keep pace just fine.  There is never a problem of speed or distance, and we don't think about mathematics.

Also, despite all theories, you've never seen me pedal and sail with the wind and tides.  Suffice to say I can haul ass depending on conditions, and I don't need a GPS or abacus to tell me that.

Just my .02

Suffice to say I can haul ass depending on conditions, and I don't need a GPS or abacus to tell me that.

Just my .02

Good one, Matt!   

Abking, I was having that very conversation with Zee this weekend.  Take a P15 in a following quartering sea and you need to be careful not to take one in the lap.  I'm going to say that the extra time I spend on boat positioning and bracing under those circumstances is equivalent to what I'd spend on a slower, more stable boat ... this is a very rough guess.

Yes, Allen, and what I key in on here is that you're having to use much more energy feeling apprehensive as you time your evasive manuevers - beyond the energy factor, I just don't want to be out there feeling apprehensive.  When windwaves are breaking they don't cover a high percentage of the surface, but most of us with lots of time on the ocean in those conditions know exactly what it feels like to have a beefy windwave break right on or around you or even turn and surf you a few feet unexpectedly.  In the X-Factor it's comfortable - in the Scrambler XT it's tolerable... 

Watch this super quick video to see what I mean:    

Oh ... and for you science geeks wanting to know more about length and its effects on speed.

http://www.inkdrop.net/qajaq/kayaking-science_WCSKS_07.pdf

Everything you ever wanted to know about the science of kayaking  ... AND MORE.

-Allen

Thanks Allen.  Most of that was a good quick review of marine science/oceanography. The bit on hull speed was very interesting, but I kind of wish it went into more depth on that.  I guess I'll have to read up on Froude and "Hull Speed".

Brian