Hobie kayak ratios...

as the width to length ratio is one of the factors that helps determine kayak stability, speed/drag..etc.

..I was curious to check the Hobies to see how they compared:

Adventure: 0.14
    Revo13: 0.18
     Oasis: 0.19 (tandem)
       Revo11: 0.21
        Outfitter: 0.22 (tandem)
         PA14: 0.23
         Outback: 0.23
           PA12: 0.25
            Sport: 0.26

Interesting! As it turns out my Caper is also .23.

My Prowler 13 works out to 0.175.

Interesting computation Roger.   You've got a good raw number geometric ratio to fundamentally compare kayaks, but it's just a number.  What does it mean?

Perhaps "moment of inertia" is more realistically the parameter of interest if you're trying to compare performance?  Performance of any one kayak is dependent on the person in the cockpit (their strength and weight), how the yak is loaded, and how it is propelled (turbo vs. stock fins and the position of the drive in a designed boat).  Weight distribution across the system geometry is more indicative of performance, along with delivered power.  You also have to consider the body of water (ocean, lake, or currents) and wind are additional forces acting on that system geometry for speed and staiblity to get that "moment of inertia" moving.  This would be a fun thesis for a masters in Engineering Mechanics.

This discussion probably gives some merit to the suggestion to GO DEMO a boat, and see if it feels right for you and the conditions you expect.

I thought red boats go faster. 

This might have been posted here before:

http://www.paddlinglight.com/articles/tutorial/how-much-faster-is-the-longer-kayak/

Red is definitely the fastest color though

Interesting computation Roger.   You've got a good raw number geometric ratio to fundamentally compare kayaks, but it's just a number.  What does it mean?

Perhaps "moment of inertia" is more realistically the parameter of interest if you're trying to compare performance?  Performance of any one kayak is dependent on the person in the cockpit (their strength and weight), how the yak is loaded, and how it is propelled (turbo vs. stock fins and the position of the drive in a designed boat).  Weight distribution across the system geometry is more indicative of performance, along with delivered power.  You also have to consider the body of water (ocean, lake, or currents) and wind are additional forces acting on that system geometry for speed and staiblity to get that "moment of inertia" moving.  This would be a fun thesis for a masters in Engineering Mechanics.

This discussion probably gives some merit to the suggestion to GO DEMO a boat, and see if it feels right for you and the conditions you expect.

I thought red boats go faster. 

excellent Barb, I agree with you on the complexity of kayak dynamics , the width/length factor came up in a thread recently as a first pass way to compare kayaks and made me wonder how the Hobie range stacked-up.

my feeling is that hull shape is the next factor and in some cases might even counteract the width/length ratio, changing how boats rank in on the water performance.   Looking to rank just by speed, I would probably set aside propulsion and focus just on drag versus load- my approach would be to run some CFD modeling of each kayak under a range of loads, graph the load versus drag for each, and compare the graphs to see which kayaks are best for the expected weight on board...bummer is, the CFD software that I use is for smaller structures (computer chips/modules)...

so I am going to jump on the GO DEMO boats bandwagon...but in my case, I am sort of locked into a Blue Oasis, since it needs to be a tandem, I love mirage drive boats, my wife likes the Blue, and I want a fast fun boat when I take it out alone...cheers, roger