Tag Archive: motorized

The world’s fastest kayak

What is the world’s fastest kayak?

The world’s fastest kayak is the Wavewalk S4, propelled by a 9.8 HP Tohatsu outboard motor. The S4 can go at a 17 mph speed (27 kmh) when propelled by a 9.8 HP motor, with only the driver on board.

What is the world’s speed record for kayaks?

The current kayak speed record is 17 mph (27 kmh). This speed record was achieved by Captain Larry Jarboe, in Key Largo, on January 17th, 2018, in a Wavewalk S4 outfitted with a 9.8 HP outboard motor.

What makes a kayak faster?

The factors that contribute to a kayak’s speed are its Size, Weight, Dimensions, and Propulsion.
Human Powered: In a paddling or pedaling mode on flat water, mono-hull kayaks with a high Length to Beam (L/B) ratio, namely very long and narrow kayaks, are generally faster than kayaks with a low L/B, which are more stable.
In choppy water, the kayak’s Stability and Balancing capabilities offered to its crew play a more important role.
Motorized: At high speeds, such as when the kayak is motorized by a powerful outboard motor, Stability and Balancing capabilities are the dominant speed factors, as the kayak moves in a planing mode and no longer in a displacement mode – The stabler the kayak, the easier and safer it is for its driver to drive it at high speed.
Additionally, kayaks that offer their driver to drive while seated closer to the motor are safer and easier to drive than kayaks that have the driver separated from the outboard motor by a longer distance.

Why is stability a key factor for speed?

Stability is defined as resistance to change. A kayak driven at high speed can flip over more easily than at a lower speed, and better lateral stability means that it can be driven at higher speeds with a lesser risk of overturning.

What is the most stable kayak?

The world’s most stable kayak is the Wavewalk S4. It is the only kayak that enables a 200 lbs full-size adult to stand on one side of the kayak with both feet, and turn around themselves as if they stood on the deck of a full-size boat. It is also the only kayak that can be driven at high speed in rough water, namely the most seaworthy kayak.
This unmatched stability results from the fact that the S4 features a patented twin hull. In this full fledged, true catamaran form, the boat’s volume is distributed along its left and right sides, where it is the most effective in offering maximum buoyancy and therefore best support for the shifting weight of both passengers and gear. This optimal performance is in contrast to other kayaks that feature conventional mono-hulls, where the hull’s volume is concentrated along the boat’s center line in a way that makes it the least effective in stability terms.

Why is balancing capability a key factor for kayak speed?

Being a small vessel, a kayak is inherently less stable than bigger boats, and therefore the ability of the kayak’s user(s) to balance themselves and their kayak effectively is key factor in the kayak’s overall stability.
Balancing capability is a key ergonomic factor for driving many types of small vehicles, both human powered and motorized.
It is particularly important in bicycles and motorcycles that offer no stability of their own, and therefore depend entirely on their users’ ability to balance them. Other vehicles that offer their users good balancing capabilities are All-Terrain Vehicles (ATV), snowmobiles, and Personal Watercraft (PWC).

What gives a kayak user better balancing capabilities?

A type of seat known as a Saddle is what all the above listed vehicles have in common. A saddle allows the user to balance themselves with their legs straddling the seat, in a manner similar to horse riding. The user straddling the saddle seat can easily and swiftly shift their weight from one leg to another, in a way that resembles balancing while running and jumping, namely more naturally, intuitively, and effectively than when seated in other positions, such as on a bench, swivel seat, chair, or in the notoriously uncomfortable and unstable L kayaking position.

What makes the Wavewalk S4 faster than other kayaks?

The Wavewalk S4 is the world’s fastest motorized kayak due to the fact that it is the world’s most stable kayak. This urivaled stability is made possible thanks to its twin-hull (catamaran hulls) and the ability of its crew to balance themselves effectively while riding a saddle seat, similarly to the way that Personal Watercraft (PWC) and other high performance vehicles (e.g. motorcycles, ATVs, snowmobiles) balance themselves and their vehicles.

The world’s fastest kayak in action (movies) –

The world speed record for vessels designated as kayaks:

Captain Larry Jarboe driving his S4 at 17 mph

 

High speed motor kayak in the ocean chop:

 

Speed comparison of S4 powered by a 5 HP vs 9.8 HP:

 

What are the advantages of a fast kayak?

The main advantages of a faster kayak is that it saves you time when you want to get somewhere, such as a productive fishery, and it makes it possible for you to access remote locations.
In addition, speed is enjoyable, and driving a fast kayak is fun.

Practically speaking, a fast and stable kayak that’s also highly seaworthy presents the advantages of a microskiff (micro skiff), in addition to being a car-top boat, and the ability to carry it to and from the beach, without depending on boat ramps.

 

10 good reasons to motorize your kayak

Wavewalk is the world leader in motorized kayaks in terms of stability, load capacity, seaworthiness, speed, versatility, mobility, comfort, and more.
This article answers the question “What are the advantages of motorized kayaks over non-motorized ones?”

1. Motorizing is easier than paddling

Not everyone can paddle their kayak over long distances, or in less than perfect conditions. Some kayakers suffer from disabilities, and others are elderly or not physically fit. Assisted paddling, namely paddling while an electric motor provides your kayak with additional propulsive power makes things easier, be it in strong wind, fast currents, or waves, as well as on flat water. When you motorize, you save your own energy, and you’re more comfortable.

2. Having a motor is safer than depending solely on paddling

A human powered kayak is an under powered vessel, by definition. In a sustained mode, an average adult paddler can produce between one tenth of a horsepower and one quarter of a horsepower, and this is very little, even in comparison to weak electric motors. In case you’re too tired to paddle back to your starting point, or due to unfavorable changes in water or weather conditions, being able to propel your kayak with a motor can be a critical factor that could save your trip, and even your life – A motorized kayak is safer than a non-motorized one.

3. A motor greatly increases your range of travel

Simply, having an extra source of power on board allows you to go further, since you can paddle to your destination, and motorize on the way back. So, whether you’re on a touring, fishing or on a photography trip, the motor allows you to cover more water, explore, and go to more places.

4. A motor allows you to take a bigger payload on board – cargo and/or passengers

You may want to take a passenger on board, or load your kayak with heavy camping gear, but this additional weight could make it too hard for you to paddle. In such case, a motor could make the difference.

5. Motors work well for trolling

You can paddle your kayak and fish at the same time, namely engage in trolling, but an electric trolling motor or a small outboard gas motor can do a better job than your paddle.

6. Driving a motorized kayak is fun!

Driving a motorized kayak can be fun too, especially if it’s a Wavewalk that’s outfitted with a powerful outboard motor. And driving standing, which is an option that all Wavewalk models offer, is even more fun – It’s comparable to skiing, except you’re going on water and not on snow, and it’s also comparable to water skiing, except for the fact that you’re free to go anywhere you want, including in choppy water and in waves, and you don’t depend on a powerboat to tow you.

7. A motor can get you to places that you otherwise couldn’t access

A Wavewalk outfitted with a mud motor (surface drive) can go where other boats can’t, and even where human powered kayaks can’t, such as mud flats, fast streams, etc.

8. Driving saves time

An S4 Wavewalk kayak outfitted with a powerful outboard motor can go at speeds approaching 20 mph, for as long as you want. This is more than five times the speed that a strong kayaker in a fast kayak (that is not a typical fishing kayak) can sustain for a limited amount of time, on flat water. In other words, a motor kayak can get you much faster to where you want to go, and back.

9. Motor boating is cool, and speed is exciting

Not everyone likes paddling, and not everyone thinks it’s cool. You may want to take someone on board your kayak, be it a child, your wife, an elderly parent, a fishing buddy, etc., and find that kayaking (or canoeing) doesn’t appeal to them, but going in a motorboat would, and to some of them the appeal would be greater if you go at high speed.

10. Helping other kayakers

Having a kayak powered by an outboard motor puts you in a unique position of being able to help other kayakers. You could do it by carrying heavy camping equipment on board your motorized kayak (realistically, only a Wavewalk…), taking passengers that aren’t fit for paddling, and by towing other kayaks.

 

More articles on these subjects –

How much HP for my S4 skiff’s outboard motor?

Developments in Motorized Kayaks

Paddling in Strong Wind

Boat stability in a kayak

Motorize your fishing kayak?

How Much Gear Can You Store Inside a Wavewalk Fishing Kayak?

Fishing Kayak Stability

Motorizing Your Kayak – Why, How, What Etc…

 

Wavewalk S4 first sea trial on windy day, with 5 HP outboard motor, Key Largo. Video and review

By Captain Larry Jarboe

Florida Fishing Kayaks

Some thoughts about the Wavewalk S4

 

Beautiful lines!  It may be the Cadillac of kayaks but it looks like a seagoing Corvette.  Is it a high performance motor yak or a portable runabout?
Super stable.  Because it looks so seaworthy, most other powerboats do not slow up when passing port to port.  No problem.  The S4 slides through wakes easily without leaving planing mode.
It seems to run a little faster than the W700 with the same motor.  I believe the wider hulls act like a pair of skis to help the boat skim across the water.  Handling tiller, camera, and a GPS at one time is beyond my skill set.
Tracking through turns while planing is wonderful.  The boat’s stern does not slide like many skiffs do.
The S4 is so easy to spin your body to face the outboard motor because the hulls are so wide.  You can keep your feet inside the vessel.
Also, the S4 is the perfect vessel for folks who are tired of maintaining their leaky inflatable tenders.  Or, people who want a lifeboat that can be used for shade or transport, too.
I still think the W700 is the boat that does it all, but the S4 is the boat that does it all, and more!

The video shows 15-20 knot wind close chop.  No problem.  Try paddling against this.

Larry J.

 

P.S. – This boat could make a run from South Florida to Bimini.  But, for the time being, I will be staying in waters managed by our Country.

 

 

 

Wavewalk S4 in gray with 5 HP Nissan (Tohatsu) outboard motor. Photo shot on the mother ship.


Larry also offers guided fishing and diving trips in the Key Largo and the areas that surround it »

 

More fishing adventures with Capn’ Larry »

Testing 15″ short (S) shaft outboard motor performance with Wavewalk kayaks and boats

This article summarizes the research that Captain Larry Jarboe, of Florida Fishing Kayaks and Boats in Key Largo, Florida did on this subject, and we are very grateful to him for this exceptional contribution.

Background –

 

Larry’s main goal in conducting this series of experiments that lasted for several weeks was to find the “sweet spot” for 15″ (S) outboards, namely a setup that would enable him to successfully outfit W500 and W700 boats with such motors, which are typically cheaper and easier to come by than 20″ (L) motors.
His secondary goal in running these extensive tests was to check the performance of Wavewalk’s TMM 700 HD motor mount, and see if we could improve it.

Larry is a passionate fisherman, mechanic, and seaman. He works as a commercial fisherman and fishing guide, and he is Wavewalk’s distributor in Southern Florida.
For the past fifty years, Larry has been involved in using, building, refurbishing and testing motors in various land and water vehicles, including electric racing cars, regular cars and trucks, a wide range of small watercraft, and big diesel engines in stern-drive commercial fishing boats, such as he still operates in Key Largo.

Means and Method –

 

In his tests Larry used five portable outboard gas motors that he had refurbished and tuned himself. Some of the motors had 15″ short shafts, and the others had 20″ long ones, and their horsepower rating ranged from 2 HP to 5 HP. He also tested a couple of electric trolling motors.

Larry conducted his experiments systematically – Being a handyman as well as a mechanic, he built a series of transom motors mounts that enabled him to mount outboard motors of both sizes in various places at the boats’ stern.
In his tests, he changed the height of the mounting plate, and/or its distance from the cockpit’s rear end.

Results –

 

There is no “sweet spot” for mounting a 15″ short (S) shaft motor on a Wavewalk, and any configuration involving the use of such size motor would inevitably result in sub-optimal performance compared to the use of a 20″ long (L) shaft outboard motor of the same power.

The main problems that Larry found with 15″ short (S) shaft outboard were the following:

Ventilation

 

Outboard manufacturers recommend mounting outboard motors with their anti ventilation plate (sometimes called “anti-cavitation” plate) immersed a couple of inches below the boat’s lowest point, which by definition is always immersed. This inevitably means that the anti ventilation plate is several inches below the surface. If the propeller rotates with its blades too close to the surface, it sucks air from the surface, and instead of rotating in water it rotates in a mixture of water and air bubbles. As a result, the propeller loses efficiency and power.

  1. At higher speed – Larry found that with 15″ short (S) motors, ventilation started to occur at about 5 mph, when the boat was transitioning from a displacement mode into a semi-planing mode, and its hulls were slightly raised, thus pulling the propeller upward and too close to the surface. The higher the speed the more extensive the ventilation and power loss. No ventilation occurs with 20″ long (L) shafts, even at speeds higher than 12 knots (13 mph), when the boat is in a full planing mode.
  2. When making sharp turns – Larry found that the 15″ short (S) motors’ propellers sucked air from the surface while he was making sharp turns. This happened since the boats tilted on their side, and the propellers got too close to the surface. In this case, ventilation resulted in loss of power as well as loss of control, to some extent, which made turning more difficult. Such problem did not occur with 20″ long (L) shaft motor, which performed flawlessly in sharp turns at high speed.

Splashing and discomfort

Splashing – In order to avoid ventilation, it is possible to mount 15″ short (S) shaft outboards at a lower level, with its propeller immersed more deeply. This can be done when a specially designed motor mount is placed several inches behind the cockpit’s rear end. However, at such position, the lower part of the motor mount’s vertical mounting plate is too low and too close to the surface of the water, and it will come in contact with the water. In such cases, the result is spray splashing over the motor’s head and into the cockpit’s rear end. No such problems occur with 20″ long (L) shaft outboard motors when mounted correctly on a standard Wavewalk motor mount.

Discomfort – When the 15″ short (S) outboard is mounted several inches behind the cockpit’s rear end, it is harder for the user to reach the motor and its controls (e.g. choke knob, starter grip), and it is harder for them to steer. This is not the case with 20″ long (L) motors that are mounted at the rear of the cockpit.

Bottom line

 

There is no “sweet spot” setup that allows for mounting a 15″ short (S) shaft outboard on a Wavewalk (500 or 700) without it incurring serious drop in performance. The way to motorize a Wavewalk is to follow the recommendations of outboard manufacturers about mounting their motors, as well as Wavewalk’s recommendations that fully coincide with them, namely to use only 20″ long (L) outboard motors with Wavewalk’s kayaks and boats.

 

A sweet spot, sort of…

 

When Larry checked 15″ short shaft, weak electric motors, he found that the ventilation problem at higher speed didn’t occur, because such motors lack the power to propel a kayak at speeds that are high enough to make it reach a semi-planing mode, or have the propeller suck in air from the surface. Knowing about such a sub-optimal performance envelope, the user already expects sub-optimal performance. This said, this rule is not ironclad, and ventilation may still occur in case the boat makes a sharp turn.even when it is propelled by such weak 15″ short electric motors, and while going at low speeds.

This is to say that Wavewalk recommends not to use short shaft motors even in the case of weak electric trolling motors.

In sum, the only propeller shaft size that we recommend for all types of motors is 20″ long (L)

 

More reading:  How to measure an outboard motor’s propeller shaft length? »

 

 

 

 

Choosing an outboard motor for your Wavewalk® 700 skiff

This article is an attempt to answer some questions that Wavewalk skiff owners ask in the process of choosing an outboard motor for it –

Short shaft or long shaft?

We definitely recommend using outboards that feature a long (20″) propeller shaft, and for multiple reasons, which are discussed in this article entitled Outboard motor propeller shaft length for Wavewalk fishing kayaks and boats »
We recommend not to be tempted by the availability and lower price of 15″ short shaft outboard motors, because such motors don’t fit the W700, and using one would never produce optimal results, even for a highly skilled individual with a lot of experience in boat outfitting.

Here is a list of long (L) 20″ shaft outboard motors currently available in the 2 to 6 horsepower range, and their HP rating:

  • Honda 2.3 HP (air cooled), 5 HP
  • Suzuki 6 HP
  • Evinrude 6 HP
  • Tohatsu 3.5 HP, 4 HP, 5 HP, 6 HP
  • Yamaha 2.5 HP, 4 HP, 6 HP
  • Mercury 3.5 HP, 4 HP, 5 HP, 6 HP
  • Mariner 3.5 HP, 4 HP, 5 HP, 6 HP

Recommended reading –

Air cooled or water cooled?

Water cooled motors are quieter but heavier than comparable air cooled motors.
The only motor featuring on the above list that’s not water cooled is the Honda 2.3 HP. It is very lightweight, and works very well, but being air cooled makes it considerably noisier.

Note: Outboard motor manufacturers recommend flushing the motor’s cooling system with fresh water after every trip in saltwater. It’s possible to flush an outboard with a garden hose outfitted with a special adapter.

4-Cycle or 2-Cycle engine?

Nearly all new small motors on the market are 4-Cycle (4-stroke) and not 2-Cycle (2-stroke).
The advantage of the 4-Cycle system is twofold –

  1. The motor runs on regular fuel, and there is no need to mix it with oil.
  2. A 4-Cycle motor is cleaner, namely it emits far less stinky fumes than 2-cycle motors do.

Some experts argue that for the same displacement of its combustion chamber (cc, volume, size), a 2-Cycle engine in more powerful than 4-Cycle one, but we think that convenience and fresh air are more important.

electric or gas?

Many Wavewalk owners outfit their W500 and W700 with electric motors in the 30 to 50 lbs thrust range, and some go as far as 70 lbs thrust. They use their electric kayaks and skiffs for assisted paddling, recreation, touring, trolling, fishing, snorkeling, etc., but we prefer not to include electric motors in our list of “real” outboard motors for two reasons, which are:

  1. Power – Although some small electric motors are offered as “outboard motors”, just looking at their basic, objective power rating makes us think that they are too weak. Kilowatts to Horsepower conversion: 1 KW = 1.34 HP, and 1 HP = 0.745 KW. Consequently, an electric motor can work well on flat water and at a moderate speed, but not necessarily in adverse conditions, namely strong current, strong wind, etc.
  2. Range of travel – A gallon (3.8 liter) of fuel costs a few dollars, and it’s enough for a typical small outboard motor to run for 4 hours at a high RPM, or an entire day at a lower RPM. You can refuel a small outboard’s built-in fuel tank when you’re on board your Wavewalk®. You can take several gallons of fuel with you on a long camping trip, and you can buy more fuel almost everywhere, while recharging an electric motor’s battery can take half a day. Therefore, gas outboard motors offer a reliable and convenient solution whose price / performance ratio is unbeatable by any electric motor available today.

Weight

All small outboard motors listed above are considered to be Portable. However, between the 29 lbs of the 2.3 HP Honda and the 59 lbs of the 6 HP motors there is a considerable difference, if you need to carry the motor by hand over a distance.

The shallow water position

Most of the small outboard motors listed here offer to lock their propeller shaft in an intermediary position between the vertical (down) and horizontal (up) positions. In this intermediary, slanted position, the propeller drafts less than in the vertical position, and this allows for driving the boat at a moderate speed in very shallow (‘skinny’) water. Therefore, if you’re looking to fish in skinny water, we recommend that you look for this feature.

gear shift lever

Most outboard motors on our list feature a gear shift level, and this is a good thing, because the alternative is a centrifugal clutch that lacks an absolute neutral position. The absence of a full neutral gear can make starting the motor a little tricky, if you’re a beginner.
Our preference goes to the outboard motors that feature the gear shift lever at the front, rather than on their side. The frontal position makes it easier for the driver to access the lever whether the motors points left or right, and even if the driver is facing forward.

built-in fuel tank

All the above listed outboard motors come with a built-in (integrated) fuel tank, and this is a convenient feature considering the alternative is to have a fuel line run from a separate tank to the engine. When you operate such a small craft as a Wavewalk, simplicity becomes increasingly important.

propeller

The propellers that come standard with these outboard motors fit Wavewalk’s kayaks and portable skiffs. Typically, these motors propel much heavier boats, which is why the propeller’s diameter and pitch which determine output in terms of speed and torque are of no real consequence to the owner of a Wavewalk under normal conditions.

price and brand

All the brands listed above are known to produce quality motors, and in fact some of them produce motors for others. For example, Mercury is a Tohatsu brand. This is to say that we see no reason to pay more for a particular name brand, and we recommend to consider only the motor’s technical attributes, and its price.

HP rating – can i overpower my skiff?

6 HP is the absolute maximum for which the W700 is rated, and this is only for its RIB model. Overpowering your Wavewalk can be hazardous, and if you use the wrong motor mount you’d be calling for trouble. This said, if you happen to own a 20″ shaft 5 HP motor and your W700 is rated for a 4.5 HP motor, you can keep your motor, and you won’t necessarily have to get a new one. Similarly, if your W700 is rated for up to 4.5 HP and you found a nice 4 HP that you like, you’d be fine with it.

motor mount

If you choose to make a DIY mount for an electric trolling motor, chances are that you’ll succeed, since these motors are so weak that they’re not likely to cause trouble. But this is not the case with the gas outboard motors in the range that features on the above list.
There are several issues to overcome with motor mounts, and the motor’s weight is the least of them. The main problem is that operating at the end of a 20″ lever, the motor’s propeller generates a great amount of torque, especially at high speed, in rough water and when making sharp turns at high speed. This torque can twist and crack a 4×2 timber, and pull out nails and screws from their place. After having seen motor mounts get broken by outboard motors ranging from 6 to 3.5 HP that were mounted on them, we strongly recommend not to build a DIY motor mount for these motors, and to use only the motor mounts that Wavewalk recommends.

alternator

Some of the more powerful outboard motors listed here can be outfitted with an alternator and an AC to DC converter. Note that such accessories cost hundreds of dollars.
The electric current produced by this system can be used to power lights on board, or to charge a trolling motor’s battery. Such setups are common in bigger boats (e.g. bass boats) that feature much more powerful motors. Although some Wavewalk owners have outfitted their W700 with two motors (a powerful one for driving and a small one for trolling), we don’t know of anyone who’s outfitted their outboard motor with an electric current generation system.

Why an outboard motor?

Skiffs, Jon boats and other small boats sometime come with other motors, among which are air drives or air motors (large diameter propellers) for running marshes and flats, jet drives (similar to personal watercraft, a.k.a. jet-ski), long shaft mud motors for going in shallow water and over obstacles, and outboard motors that run on propane.

While each of these motors offers certain special advantages, and we’d love to see the W700 outfitted with any of them, as well as with other propulsion systems ranging from sails to oars, and even pedal drives… we think the common small outboards such as we listed here offer the optimal mix of price, performance, reliability, versatility, ease of use, and ease of maintenance – Just think how common are boat dealerships and repair shops that service these motors… And if you know how to use your outboard motor and you take care of it, it’s truly a wonderful thing that you’d enjoy for years, and possibly even decades.