Just curious about the difference in performance between the 10’ versus 12’ kayak. Some reviews have implied that the longer the kayak, the better it tracks. Second questions, what about speed – is a longer kayak faster than a shorter kayak? Are there any other functional differences between different lengths of kayaks?
Too simple a question. A longer kayak of the same type hull and similar aspect ratio would be faster.
However personally they are both too short.
Not enough to make a big difference when it matters.
Go at it the other way around. Figure where and how you’ll paddle and let that decide the boat and gear.
The question seems simple, but unfortunately much more plays in than just the length change. There are only a few examples I can think of where you change the length of a boat without changing something else in the design (width, rocker, keels added, etc.) that would also impact the comparison.
In general, a shorter boat will maneuver easier and track (go straight) less well. A shorter water-line boat will have a lower top speed than a longer boat. Note - this is max speed, which is different than how hard it will be to paddle at a certain below-max speed - that is more related to friction and wetted surface and the like.
Problem is, especially at shorter lengths, is that design changes need to be done when changing lengths. To support a paddler of a certain weight, if you go from a 12 foot to 10 foot boat, you either need to go wider or the boat will sit lower in the water. Both of these will cause a boat to be slower. And manufacturers know that shorter boats don’t like to go straight, so they start designing in keels and the like to help the boat go straight.
I come from a sea kayak background. Over the years, I have found my sweet spot to be 14-15 feet with moderate rocker. I’ve owned many longer boats, and find they track too well for me. For example, if I was in a Necky Looksha IV (17.5’), to do a 360 using sweep strokes could take 8 or 10 strokes. At the other extreme, if I was in a Jackson Karma (<13’ boat), it seems like a single flick of a sweep stroke and the boat has done more than 180. The sweet spot (say a Dagger Alchemy - 14’), I can turn in a few strokes, but the boat still can maintain a straight line easily enough.
Someone who comes from a whitewater background likely thinks these are all way too long. It is all relative to what ones does and what one likes.
Peter-CA has summed up much of it nicely. I also feel that the 14-15 foot range is a satisfying middle ground for hull length, balancing tracking and maneuverability, at least if the boat is well designed.
A major design difference between a 10’ and 12’ boat is whether the boat has zero, one or two sealed compartments. Two bulkheads sealing front and back compartments is the best for the sake of safety, i.e. flotation. A boat with no compartments (or only one) is considered unsafe in some situations without float bags. Longer boats are more likely to have bulkheads.
Re performance, theoretical ‘maximum’ hull speed is proportional to the square root of the water line length. Going from a 10 ft hull to a dimensionally similar (identical in proportion) 12 ft hull should give a theoretical increase in max speed of 9.5%. However, there is no real maximum , it’s just a point on the resistance curve where resistance starts to increase quickly with speed.
At lower speeds, performance is dictated by skin friction, which is proportional to surface area. Area is proportional to length squared, so going from a 10 ft hull to a 12 ft hull should increase skin friction by 44%. The hulls probably aren’t proportionately similar (length to width ratio tends to increase with length), so the increase is probably more like 20%. However, skin friction is only part of the total resistance of the hull, so the overall increase in resistance will be less than that.
Depends on the width and weight of each and lastly the “engine”
And the weight of the engine. If you are over 200 lbs, forget those short boats. You will put them too low in the water for efficient Paddling.
Functionality. I generally think the function of short boats is to navigate skinny rivers or creeks or play in the surf. Since I paddle bigger, more open waters and cover longer distances I use a 14 or 16 foot boat. That’s their function. (I need to paddle more. This year I’ll paddle more, dammit).
@Rex said:
Functionality. I generally think the function of short boats is to navigate skinny rivers or creeks or play in the surf. Since I paddle bigger, more open waters and cover longer distances I use a 14 or 16 foot boat. That’s their function. (I need to paddle more. This year I’ll paddle more, dammit).
Me too!
@Sparky961 said:
Not enough to make a big difference when it matters.Go at it the other way around. Figure where and how you’ll paddle and let that decide the boat and gear.
Once we figured that out, realized we did not need anything larger than our 10- 12ft Eddylines. No desire to go far, go fast or being gone more than an a couple hours at a time. Just out for leisurely float amongst the lily pads.
Maybe with age, a bit of wisdom too!
@Yooper16 said:
@Sparky961 said:
Not enough to make a big difference when it matters.Go at it the other way around. Figure where and how you’ll paddle and let that decide the boat and gear.
Once we figured that out, realized we did not need anything larger than our 10- 12ft Eddylines. No desire to go far, go fast or being gone more than an a couple hours at a time. Just out for leisurely float amongst the lily pads.
Maybe with age, a bit of wisdom too!
Indeed. I remember when I first started out with a chain store 10 footer. It was so darn simple to cart around for local paddling. I miss that part sometimes.
I do enjoy traveling far from shore in more remote locations though, so that narrows the choices for my own boat/gear list.