New small boat patent

Patents

Thanks Matt

Like other things in life, it's a matter of priorities:
The biggest markets for boats using the 'W' invention are in the US, and this is why it was essential to patent it here.
Patenting in additional countries is difficult, expensive and not necessarily cost-effective in view of the relative size of those markets and the efforts required to develop them.

BTW, I uploaded a new page with a number of possible concept designs in various 'micronautical' applications: http://www.wavewalk.com/BOAT%20DESIGN%20GALLERY.html

You're also welcome to visit my gallery here on BoatDesign.

Yoav

 

Yoav,

I'm a long-time paddler and a multi-hull fan. I like what you've done! For certain applications your boat makes a lot of sense -fishing, carrying kids/pets, and as a dinghy for a big boat. A few questions:

1. Have you researched a longer boat for tandem use and greater load capacity? More suitable for longer trips? Obviously that means a large tooling expense for you, but have you done any prototypes/designs?

2. Does the Wavewalk have much rocker? Or is steering accomplished solely with lean? If no rocker, have you payed around with that variable?

3. What's the hull profile like? Looks like it has a flat bottom on the inside, similar to a dory. Did you cant the bottom(s) to facilitate turning?

Very cool.

 

Thanks Deering,

1. We took 2 short plastic W kayaks, cut them and welded them together (sounds barbaric, I know ) to create a 15' long experimental model. The thing looked like ...well, hmmm...-like something you don't want to step on let alone sit inside and paddle it, but it performed really well: considerably faster and stabler than our small production model. There are some pictures of it on this page: http://www.wavewalk.com/BOAT%20DESIGN%20GALLERY.html
In fact, I'm looking for people interested to cooperate with me on building long W kayaks/boats for paddling and other applications. The design is easy and partly done already.

2. The W kayak (W1) has little rocker. You don't need a rudder for it to track or turn - Same thing for the 15 footer we tested.
BTW, there's a lot you can achieve with W kayaks/boats simply by changing your location along the longitudinal saddle, see details in paragraph about surf launching in this page: http://www.wavewalk.com/SURFING.html

3. You can use any profile you want. In the case of the small, narrow W kayak (W1) we used an almost square profile, see bottom of this page: http://www.wavewalk.com/PADDLING%20POSITIONS.html
It increases lateral stability by acting as an 'extremely hard' chine (see demo movies page) but even so, turning is easy because of the ability to lean into the turn and use the inner hull as an 'ad hoc rudder'.

Yoav

 

Is it just me, but isn't the center of gravity rahter high in that, meaning that although it has a higher initial stability it will have tendency to toss you like you're riding a horse at a rodeo?

I'm thinking that, in waves, it will float with the surface of the water, and because of that, it will actually be easier to tip over because of that extra high cog?

 

Hi Andre

Hi Andre, welcome to boatdesign

The CG of W boats is indeed higher than that of comparable monohull kayaks, but the total stability offered is better.
This has to do with 2 things:
1. The W's buoyancy is distributed along its sides instead of being concentrated along its longitudinal axis without contributing much in terms of stability.
2. In combination with #1, the W passenger/s are offered the possibility to balance themselves effectively with their legs, and indeed your analogy with horse riding is highly appropriate.

The passengers' role is critical in micronautical design. Static stability is often not sufficient and the boat's overall stability (static + dynamic) depends on the users' successful interaction with it. This is of course different from what you find in bigger boats, where the body position and movements of a single passenger rarely have a critical effect on the boat's behavior.

You can watch some videos demonstrating the W stability in different environments and applications on this page:
http://www.wavewalk.com/DEMO%20VIDEOS.html
And you can also read about related stability, biomechanic and ergonomic issues on this page:
http://www.wavewalk.com/PADDLING%20POSITIONS.html

Yoav

 

Thanks for your welcome and your explanation

It still seems a bit out-there, somehow, but I'm nowhere knowledgeable enough to be able to qualify that enough. Your explanation seems like, to use another stupid analogy, to be riding a bicycle, where you really move the bike in and out of the cg in order to keep it balanced, hence why it is hard to do if it's icey. Smack!! Wham!! like sitting on top of a pole with a wheel under it.. As oppose to the traditional design where your bum is below the cg, thus levelling the forces out a bit.

Andre

 

Bike analogy

Andre,

A kayak designer once told me that 'The W is to the [traditional] kayak what the bicycle is to the unicycle'...
By that I think he he wanted to say that the W is more stable but the unicycle is more fun (in his opinion) .
The W passengers apply their weight through their legs and feet at the boat's lowest point, that is at the bottom of the hulls - below waterline. Each hull is buoyant enough to offer support for the user's entire weight.
This video demonstrates the reduced effect that lateral waves have on the W boat: http://www.wavewalk.com/Surf_02.WMV
And this one shows how you can jump in this 25" (63 cm) wide boat:
http://www.wavewalk.com/Stability%20-%20Jumping%20in%20the%20boat.WMV

Yoav

 

Well, the problem, as I see it, is still the same. Because of the higher centre of gravity, it's like sitting on top of ball, instead of in "the middle". I don't doubt your numbers or anything, I simply don't believe that it is any more stable than a traditional kayak, especially not when there's a bit of sea. It's way too tall for my liking, that in itself (and in my mind) is making it inherently "instable".

To go back to my bike-allegory, a bike, when the wheels are parallel, are constantly out of balance, and the slower you go, the wider corrections are needed to keep it under you, until, at the extreme (a stand still), where you need to have the front wheel almost perpendicular, using both braking and accelaration to make the bike move back and forth beneath you.

Now, you may think that I'm taking this off-topic, but I'm not, I'm getting closer to your quote about the unicycle.

The difference between a unicycle and a normal bike, is that bicycle is that the ordinary bike will go faster, be more stable, is safer, and easier to use than the unicycle that need's to be constantly corrected, accelerated and deccelarated in two directions, often simultanously.

It's funny, though, that you bring up the unicycle, because that is sort of like my example of balancing on a stick, making it much harder to change course, and more importantly, the unicycle (read "the W-boat") is much more delcate on a rough surface (read "waves").

Now, the jumping part: The reason that it can be jumped with is because of the movement of mass, with your hips and legs using a platform to accelerate your upper body upwards with more speed/mass than your legs are weighing, hence you will jump. That has little to do with stability.

Why it hasn't anything to do with stability, or why I, personally, don't see it as such is because - well, let me start of a bit off-topic to set the scene:

I'm _still_ - at 33, pretty good on U-ramps. Both on BMX's and rollerskates and blades. I can (with a good three tries nowadays) still make a Mctwist (a saltomortale with a twist) on the blades, and I can still salto with the bike. And here's the catch: I can drive down the ramp on the rear wheel, I can jump on my front wheel, and on my blades I can do all sorts of tricks - jump and land on the front wheels alone after a 1080, and jump long and high, landing on one front and one rear wheel only (on the blades). Yet, it's definately not a stable set up. It doesn't take much to go wrong. (I'll skip the part with all my broken bones ...).

Speaking of which. A BMX, in itself, isn't very stable, and that's the point. It's short (making jump tricks easier (bigger height)), and the handle bars are wide (giving more torque when twisting it)).

Why do I use those examples? Well, because a) I can jump and do tricks on those contraptions just fine. b)Neither are stable per design, c) both demand much more than something low, and longer, and d) neither can seriously be used for the long haul, neither can they be considered to "easy" to use.

And just one other reason I brought those things up: you can jump on those as well, but that is simply a matter of shifting weight upwards, easily acheived on roller blades, and almost as easy on a bike (i.e. you have to lower the saddle). It doesn't say anything about the stability in itself.

Sorry about the length of this post

Andre

 

Show me

Andre,

Beliefs can thrive in the absence of evidence, so let's talk about facts:

Show me people paddling standing in traditional kayaks...
Show me people fishing standing in traditional kayaks...
Show me people surfing standing in traditional kayaks...
Show me people jumping in traditional kayaks...
Show me people sailing standing in traditional kayaks...
Show me people paddling in the surf in parallel to incoming waves in traditional kayaks...
Show me people steering a kayak by leaning into the turn...

Regular people across the USA have been doing all these things and more with their W kayaks - There's nothing 'theoretical' or related to 'belief' about these proven facts.

Again, normally you don't 'sit on top' of a W but you ride it with most of your body weight resting on your feet below waterline while your legs are doing what they're good in doing: support and balance you.
It's a dynamic approach (reminding of canoes) while the approach in traditional kayaks is static - your legs are stuck forward and play a minimal role in your balancing, control and propulsion efforts.
More on these issues: http://www.wavewalk.com/PADDLING%20POSITIONS.html

Yoav

 

That's not what I'm saying.

If you read my posts again, you would see that I point to the fact that it is indeed more stable relative to the surface, making it more unstable in the real world.

Why should I show you pictures of anything. You're the one that have the math calculated, you're the one that has a vested economical interest in selling your stuff.

Jumping, as I explained isn't that much of a deal, especially in flat water. I think I have already explained why. Several times.

Standing surfing? Has that to much to do with stability? Seriously, how stable is a semi-round-bottomed surfboard?

On another note, that "jumping" that is showing looks more like pushing the platform down, not actual jumping.

The people surfing in parallel? People do that all the time. And no matter how many tries it must have taken you, the problem of the inherent lift you have in two hulls will make one side lift faster than the other, simply because it's closer to the crest, so to speak. You can show me all those fancy videos. Just like I can show you fancy videos of people doing something else. That is not to say it is a good design because of it.

The fact is, no matter how math you give me, or try to make me show to you. You _do_ have a higher center of gravity, and you _do_ have the "lift" based on two hulls, making the CG describe a much wider arc when in waves coming from the side, hence it will have a bigger tendency to tip over sideways.

About people turning by leaning - that also has abosolutely zilch to do with seakeeping - A box, with the ends of the bottom turned upwards would do that no problem. Now, place a stool on top of that box to get the cg up higher, and call that more stable. I mean, you can "jump" in that box too, you now.

No matter if you prefer to call it "riding" it, or as I do "sitting on top", the difference is pure semantics. The only difference being that you have something _between_ your legs when riding, and when you sit, you can have your knees together.

Keep defending it. The thing is, that no matter what you say, your cg is higher, and it's more prone to tip over because of this and it's stability. THe stability is indeed stability in flat water, but I wouldn't trust it in any kind of sea, frankly.

 

I forgot:

What happens if the paddler fell out un water over his head? That boat can carry an awful lot of water. How hard will it be to get back "on board" and get the water out?

Why isn't there a video of that?

Even if you believe in your kayak, it should still be prepared.

When the guy jumps, the hull seems to be twisting and flexing a lot. Does this lead to less stability?

Why is it the same person in all the videos. Why not an "every-day" paddler?


Edit: Apparently I forgot yet another thing. Because it turns when it is leaned relative to the surface, won't the kayak then have a tendency to go _up_ a wave when going paralel - making it even more likely to turn over?

 

To go back in you practice a commom 'wet entry' (it's a padders' term) from the back. You can do it without assistance from other paddlers. Thanks to the boat's higher stability it's easier than getting back into a traditional kayak.

This model is molded from Polyethylene (like most kayaks), which gives a certain flex to the hull, and allows for extreme mechanical stress such as when a 200 lb (90 kg) person is jumping up and down in it or from side to side. It's not absolutely necessary but in this case it actually adds stability.

The photos and videos on the website show different people, including women and children - all amateurs. There isn't even a single photo or video of a professional paddler.

In lateral waves the W paddler leans into the wave and just keeps paddling (see videos) - Don't try this with a traditional kayak

 

What about all my other questions, Ice?

 

You can keep paddling even with a few gallons of water in it.
If too much water gets inside you can take it out using a small bucket or a bilge pump - exactly like you'd do in a traditional kayak or canoe.
If you're close to shore (e.g. when surfing) you can pull the boat out and drain it by simply overturning it.
If you outfit the W with side floatation and you bail out on time chances are it won't even capsize:
http://www.wavewalk.com/Outfitting%20Your%20W%20boat.html
http://www.wavewalk.com/SURFING.html

 

W Kayak outside voice

Fellas,

As an interested observer in your discussion, let me weigh in since the fireworks have died down.

I am an experienced kayaker (by no means a "professional" but with many years of sea kayaing, and a bit of river kayaking in big water). I also own a larger power catamaran, and have studied cats fairly extensively. I'm an engineer, though don't claim to be a naval architect.

Both of you have valid points.

Bagger - your position that the VCG is higher is obviously correct. And all things being equal, higher VCG equals less stability. But all things ARE NOT equal. I think you are stating that the W kayak will ride parallel to the water surface at all times, so when encountering a steep enough wave on the beam the kayak will tip enough that the CG falls outside the footprint of the hull and capsize occurs. That would be a correct interpretation in an entirely static situation - if the rider was just a lump of clay that might happen, though it would have to be an awfully steep wave face.

In reality, the rider can have a major effect on the response to the wave simply by simply leaning into it, and that lean is made more effective by the fact that buoyancy is far outboard - the lean doesn't have to be very much to get the CG inside the footprint. Also, the hulls don't just ride on the surface - they sink into it which means that to some extent they keep the boat more plumb than the wave surface itself.

Would I paddle a W boat down the Grand Canyon? Not a chance, because I don't believe it can be rolled back upright (assuming an appropriate cockpit and spray skirt). And the "point of no return" will happen very abruptly. An experienced river kayaker can play with that tipping point to an amazing degree with a monokayak. But the W isn't targeted towards the Grand Canyon.

I think your perception of "top heaviness" is somewhat distorted by the fact that the boat is only 10 feet long. Stretch it out to a normal sea kayak length of say 17 feet (5-6m) and the proportions would look better, though still top heavy.

Your points have been argued ad nauseum about the big boats (catamarans vs monohulls), but tank testing has shown that in general cats are inherently far more stable and less likely to capsize in conditions that will tip a monohull.

The key advantages in my mind are faster displacement hulls due to higher L/B ratio, better initial stability, and greater rider comfort.

Yoav, Bagger raises some good points. And I have a few of my own.

The jumping stunt doesn't demonstrate much, and appears to have limited value in the real world. If I saw Bagger jumping on his skateboard I might be led to believe that a skateboard is a stable platform (it's not, proven by my recent unhappy experience on my nephew's).

The wet entry point is another good one. You should show that on your website. And why not put bulkheads or foam into the ends of the hulls to provide flotation? With that I would bet that a person could ride in it almost competely full of water.

I haven't paddled a W, but the appeal of paddling standing up doesn't resonate with me. What's the point? Do people do it a lot? Is it faster or more efficient? A catamaran gains its stability from the separation of the hulls. If the beam is being limited by retaining the ability to paddle standing, why not sacrifice that capability and get a wider, and significantly more stable boat in the seated position?

Your website makes a lot of comparisons with monohulls. If I had read your website starting paddling, I would have been sure that before going to my certain death I would have been cold and uncomfortable. Good for marketing, but not true!

I've spent many hundreds of hours in a kayak, and have never capsized. Where I paddle (SE Alaska) your kayak would be much colder and wetter. It's often chilly here, and it rains a lot. A monohull kayak has a nice snug cockpit with a sprayskirt to keep rain out. Your boat is exposed.

I fish out of my kayak - brought up a 250 lbs halibut a couple years ago. A W would have worked easier, but it's definitely feasible in a monokayak.

Your website articles make it sound like a monokayak requires constant vigilance to keep it upright. When I've fished I tether off my paddle and let it float with me, ignoring the conditions entirely. Sometimes it's been pretty rough but I don't even look at the waves. A well designed monokayak can handle some amazingly rough water without rider attention. I suspect a W would have been a rougher ride, though no less stable.

Yoav, an area you should market to is the boating community. Any boat that is too large to beach needs some sort of dinghy. Generally that means some sort of inflatable or rowing dinghy. Your boat will outperform any small rowing boat, and it has the stability and large cockpit to permit easy entry from a boat (I have standard kayaks for my boat and they require some gymnastices to get into safely). It's also small and light enough to be strapped to the roof. See if you can get into West Marine.

Enough babbling...