Kayak Length vs Maximum Speed vs "Typical Touring Speed"

[BillEvans]

So another new kayaker looking for their first kayak with newbie question. Thanks in advance.

So on one hand I often read that if you want to keep up with your kayak group you “need” a long-ish kayak. And those number are often in the 16-17ish plus feet. And then folks will say that ultimate speed only works if you can provide enough power and need to go that speed. Otherwise the extra length is just drag and wasted effort. And “normal” touring speed is often quoted as being pretty modest compared to most boats maximum hull speed. And I realize that tracking and storage comes into play as well. So yeah, I’m a bit confused.

The 4 boats I’m currently thinking about are the Current Designs Karla LV & Sisu LV and the Norse Embla & Ask. Would the Karla at 15’ 4" be painful to tour with (provide the space was adequate)? In my limited (5-day course with an overnight) I quite enjoyed playing in the small tide rips and such so I think I would appreciate a boat that excels in that.

Anyway, thanks in advance for anyone willing to chime in. Cheers, Bill

[Brodie]

This is a complicated question so you are not alone in being confused. Your paddling power and efficiency are very large factors in this equation that are hard to quantify. You can tour in any kayak with sufficient volume to hold your gear and that has the appropriate level of safety features for the water you want to paddle in. But let me throw out something that might help with the confusion of why longer boats are often suggested.

The longer the waterline of a vessel, the higher its “hull speed” is. Hull speed is really just the speed at which the wavelength of the waves produced by the hull equals the waterline length. Hull speed really doesn’t mean much on its own as narrow and light hulls like kayaks and catamarans don’t require that much more power to get past “hull speed”. But power is the key here. The speed vs power curve for all displacement hulls (even kayaks) starts to go up rapidly as “hull speed” is approached and passed. At some point the power needed to achieve a certain speed becomes almost infinite. But the main point is that the power needed to go faster starts to increase quickly the faster you go.

So, the point. A longer waterline (overall length really means nothing in this discussion) has a higher “hull speed” and consequently a higher speed where the amount of power required to go faster starts to increase rapidly. That means that at a lower speed, the power required to maintain that speed is less than for a shorter hull (ie you are further down the power curve). So to cruise at 3 knots (a reasonable speed for most paddling groups) it will take less effort (power) in a 16’ waterline kayak than it will in a 12’ waterline kayak. Add in the extra width of the shorter boat and the difference gets even bigger. If you’re a strong paddler or paddling shorter distances you may not notice this. Less strong/less efficient paddlers and longer distances will amplify the difference.

There is a caveat about kayaks that are too big - if the hull has too much wetted surface then the speed advantage can be negated out by the skin/frictional drag. Generally this is only seen in small paddlers paddling large HV boats. Wind resistance can also be a problem for smaller folks in big kayaks.

[Bakerman]

You keep mentioning keeping up with your kayaking companions. What do they paddle? How do they paddle?

We belong to a few kayak clubs. In one the paddlers are “drifters”. In an other there are paddlers that have done the Florida CT, a 1500 mile paddle. Keeping up with one is too easy and gets frustrating. The other is a constant 3.5 mph average.

[rstevens15]

As mentioned, you will want to have a similar boat to what the others in the group have. Your level of skill and conditioning will also play a good part in keeping up and doing distance, and hopefully these will improve over time. A properly executed forward stroke is very important.

For playing in tide rips and such you would probably want a rockered hull, which trades off a bit of speed and tracking for maneuverability. A shorter boat is generally a bit more maneuverable, again trading off some hull speed.

All boats are a compromise. No one boat excels at everything.

[SeaDart]

Buy a boat you really enjoy paddling, transporting, storing , owning and playing in moving water features.

You’ll soon discover that buying a boat you can “keep up with the group” is not what brings you kayaking joy.

IF you want to “Keep up” buy a road bike and buy a lycra racing suit and spend your weekends “keeping up” with the other lemmings.

[PaddleDog52]

You physically description is?

Height ?

Weight?

Most groups I have paddled with are fairly slow 2.5 mph or less. So I haven’t gone in a group in years. Ask how fast your groups are someone keeps average trip records I’m sure. Thin is fast but are you ready for paddling a 20-21" hull?

[BillEvans]

@ Brodie Thanks that was insightful and cleared some of the cobwebs. And there’s a “small” chance I’m over thinking this.

@ Bakerman I don’t mean to over emphasis paddling in groups. It just seems that paddling in groups comes up as a reason to purchase a certain length kayak and I’m trying to understand the reasoning. And answering your question. Currently, when I get a kayak, I expect to paddle mostly alone.

@ rstevens15 Thanks. I get that all boats are a compromise. I’m just trying to get a handle on what how much you’d give up touring in a “play” boat.

@ SeaDart LOL I’m gonna need to run and get some Windex for my laptop screen. Great advice, thanks.

Thanks folks for the great advice. Appreciate it.

[rival51]

@BillEvans

The 4 boats I’m currently thinking about are the Current Designs Karla LV & Sisu LV and the Norse Embla & Ask. Would the Karla at 15’ 4" be painful to tour with (provide the space was adequate)? In my limited (5-day course with an overnight) I quite enjoyed playing in the small tide rips and such so I think I would appreciate a boat that excels in that.

I don’t know anything about the Norse kayaks but the Karla would be good fun in the tide races. I have a friend who has one & loves it in bouncy stuff. Not much room for camping gear though. The Sisu is a larger iteration of that hull and would have more room for camping gear although the Prana would be the kayak in that line for week+ trips.

[willowleaf]

I’ve regularly paddled a dozen different models of touring kayaks ranging from 13’ to over 18’ over the past 20 years and currently my favorite all-around boat, especially for open water maneuverability, rough conditions and effortless speed is a composite Perception Avatar. At 16’ x 22.25" by 11" depth and 50 pound weight, double chined with skeg, it is very similar to both the Sisu and the Embla. Considering what your expectations are, if you are the right size for either boat I think you would be happy with either. (For reference, I’m 5’ 5" around 150 lbs and an intermediate paddler who prefers Greenland paddles.)

[GregofDelaware]

Not sure how much our experience will help, but here it is. When we started kayaking (just my wife and myself, no groups), we had different kayaks, though both were about 16 feet long. Her’s was an Eddyline Denali, now called the Sitka I think, and comes in 3 sizes. Mine was WS Zephyr 160.

Denali: 15.25 ft long x 24.5 inches wide
Zephyr: 16 ft long x 23 inches wide

As beginner kaykers, she loved the roominess and stability of the Denali.

But she always felt, and frequently mentioned as we kayaked, that it was a chore for her to keep up with me, and that the wind was making it a chore to go where she wanted, even with the skeg deployed.

Our next, and current, kayaks are the same model, we have two P&H Cetus MV kayaks.

Cetus MV: 17.9 ft long x 21.5 inches wide

She doesn’t complain anymore about keeping up or the wind making it hard to set a course. and even though my “engine” is more powerful than hers, I find that I do not have to do as much holding back as I used to in the old kayaks. And I found it interesting how much faster the Cetus felt compared to my Zephyr.

One more data point. In 2020, our son kayaked with us about weekly during the summer. He was using an Oru Coastal XT Kayak.

Coastal: 16.2 ft long x 25 inches wide

He had no trouble keeping up with us in our Cetus kayaks and had a lot of fun. But the next summer, we swapped kayaks and he was blown away by how much easier and “turbo charged” the Cetus was compared to the Coastal. And my time in the Oru was that it had a lot of drag, due to the folds at the bow. Noisy water turbulence. So, compared to my Cetus, it felt like a chore to keep up.

The kayak makes a difference, but it is not as simple as length though that does play a role. Width, hull design, and other factors will come into play.

[BillEvans]

That was a ton of great info. Thanks .

[castoff]

I play in the surf in a British style sea kayak, and paddle long distances with camping gear. It is 17’ 4" long and 21.5" wide with noticeable rocker. It is a decent compromise for what I like to do. I have paddled it on tight twisty rivers with downfalls but not rapids, swamps, lakes, marshes, and the Ocean. My weight is 185 and height is 5’ 11". I paddle with Euro, Wing, and Greenland paddles depending on what I plan on doing. Correct paddling technique is very important.

What you may come to find is that you will want different boats for different types of paddling. I do most of my river, swamp, and what little whitewater paddling in canoes, and surf play, open water, and long-distance paddling in sea kayaks.

[PaddleDog52]

Length has an effect but I don’t think very much at even low speeds. Hull glides effortlessly at any speed even with two strokes. Don’t think wetted surface has much effect on my Extreme.

[BillEvans]

Wow! That’s a stunning boat. Looks really fast just sitting on its stands.

[PaddleDog52]

700 bucks Current Designs Extreme

[mcteague]

Interesting article on the subject by Nick Schade.

I’ve added his synopsis for the TLDR folks:

After years of watching people paddle all sorts of kayaks, I have come to the conclusion that for most paddlers 14’ of length is really all they need. I paddle long boats a lot as well from 17’ sea kayak to 20’+ surf skis. It takes a lot of strength, stamina and physical fitness to gain the speed potential advantages that longer boats offer. Short boats do tend to be wider which increases drag, but if you can find a reasonably narrow boat in the 14’ range, chances are that will be as fast as you will be comfortable paddling. Constantly seeking a longer boat to go faster will not do you any good if you don’t also spend the time to train and increase your fitness

Are Longer Kayaks Really Faster? | Guillemot Kayaks

Tim

[sing]

Reaffirms a lot of what has been posted over the years, that length is just one factor that impacts speed. But, it won’t stop those seeking to reduce it to THE ONE “magical” factor to make up for shortcomings in other areas.

sing

[Kevburg]

I can offer my personal observations on this.

My '70s Clearwater kayak is 32 lb, 14 foot long with a 24 inch beam and no rocker. I typically cruised around on this at somewhere around 5 mph on 12 mile trips. When cruising I could plainly see that with every stroke the bow rose up and fell back again. I interpret this as some of my energy was wasted climbing my own bow wave, and that clearly means I was limited by hull speed.

I kept that in mind when shopping for a new boat. My Epic 18X is 42 lbs, 18 foot long with a 22 inch beam and no rocker. My cruising speed is the same. I do not see any sign of the bow bobbing up and down, nor do I see much of a bow wave for it to bob up and down on.

That difference in bow wave height is important because the bow wave is lost energy. The cross sectional profile of the Clearwater is wider and flatter than the Epics, which is rounder and has a deeper draft. I suspect that the Epic’s bow wave wouldn’t be much higher if it were only 14 feet long. The Epic’s more efficient hull shape has a bigger effect on my speed than length does.

My recommendation: if speed is your primary consideration, look for a very tippy round-bottomed boat in the 14 foot range with no rocker, narrow as you can handle.

[BillEvans]

Thanks again for all the great info and advice. I totally get that everything is a trade off (Aerospace Engineer in a past life) I’m just trying to get a feel what one might gain or lose with different choices.

I’m off, ferry gods willing, to Vancouver Island to demo some boats. My lack of experience means I will mostly be focusing on fit and comfort. Should be fun and I love Vancouver Island.

[TomL]

I’m attaching a link to a previous thread on the same subject.

Correlation of hull length and speed

I’m not knowledgeable about many aspects of kayaking but am curious about the relationship between kayak length/ width and efficiency/speed. Looking at similar hull designs like the Tsunami 12.5, 14.5 and 16.5 suppose a paddler put out the same energy in all three boats. Is there a way to calculate or approximate how much faster the longer narrower boat would travel. If you have a hull 2 feet longer and 1.5 inches narrower would the speed efficiency gain be like 5% or 10% or more. I’m sure t…

Lots of interesting info…note the one study that says a Sitka ST at under 16 feet is the most efficient boat at all speeds for a 140 pound paddler.

If I think about that highly rockered 15 footer you’re considering and using my canoe experience I think it should cruise just fine because it has good length and it’s narrow. In the canoe world rocker makes the boat feel easier to accelerate and you may like that feeling…I sometimes cover the most miles in my 15’ Swift Osprey because it’s so effortless even if a touch slower than my fastest canoes.

My canoes aren’t slow (for canoes) and I can generally outrun kayaks that aren’t sea kayaks and I’d expect that 15’ x 21" play boat to be able to pass me pretty easily.The devil is in the details but I think you’ll be just fine touring in that play boat.