Tag Archive: kayak stability

More insight on the design of the W700 catamaran – kayak – boat…

Wavewalk prefers to use the term Twinhull rather than Catamaran to describe its patented invention because its design does not fit the typical catamaran form, which implies two hulls of the same size that are placed at a considerable distance from each other, and attached by means of a wide structure (deck) from the top of which the boat’s users operate it –
The twin hulls of the Wavewalk boat form are close to each other, and they are attached by a narrow bridge located at the center of the boat’s cockpit. The passengers sit on top of the bridging structure called ‘Saddle’, and they operate the boat from within its cockpit.

Like all catamarans, the W boat design is subject to forces that pull its two hulls apart, especially under heavy loads. Different catamaran designs address this problem by different means, depending on factors such as the boat (or ship) size, materials from which it is built, etc.

Wavewalk’s first production series was the 300 (2004-2010) and its second production series is the 500 (2009 – ). Wavewalk chose rotational molding as a production technology for both series, and in fact, most modern kayaks are rotationally molded from Polyethylene, which is the most suitable polymer resin for this application.  Since 2014, boats from W500 series are outfitted with a structural element called ‘Saddle Bracket’ which takes care of excessive loads.
The 700 series is bigger than the 500 series (dubbed the world’s best one-person fishing boat), since it is designed to carry a crew of two large size anglers and their fishing gear, while being propelled by an outboard motor.  Due to technical limitations stemming from its large size and complex form, it could not be rotationally molded in one piece. Therefore, Wavewalk had to come up with a two-part solution, as shown in this instructional 3D animation video:

 

The Saddle is attached to the Twinhull by rivets. After the riveting is done, the rivets are waterproofed.

This innovative solution offers several benefits to the users, including light weight (just 80 lbs for the basic W700 model), resilience, strength, and durability.
The W700 saddle is watertight, and provides flotation in case of an accident.

A two-person motorboat that you can easily paddle and car top

It’s almost here, the 700 series from Wavewalk.

People who fish out of a W500 or W570 would tell you that it’s the best fishing kayak out there, or the best one-person fishing boat. Soon (in July), Wavewalk will started shipping boats from its new 700 series, and its goal is to have people who fish from it say that it’s the world’s best two-person fishing boat.

What attributes will this new craft have that could turn it into the world’s best two-person fishing boat, according to its future users?

Well, to begin with, it’s roomy enough for two large size anglers to stay in and fish. Its 7’8″ long and 31″ wide cockpit allows for this. Its patented twinhull form provides the stability for such a crew both when fishing (seated or standing) and motorizing.

With its 580″ load capacity, it couldn’t take more than two large-size anglers and their gear, plus an outboard motor, but we’re looking for the best two-person fishing boat, aren’t we? It is true that most fishing boats out there have a bigger load capacity, and can take a crew of more than two anglers, but the reality is that in most cases, the crew is comprised of one to two passengers, and seldom more.

The basic 700 model weigh 80 lbs without the motor attached to it. This means that it’s a car top boat even if one person has to transport it.

So what benefits does the 700 come with, and what problems does it solve?

To begin with, the W700 solves the problem of boat transportation. It’s a trailer-free boat, and this means it takes less storage room at home, it doesn’t require a trailer… and it enables its users to launch and beach anywhere they want, without having to start their fishing trip at a boat ramp, and waste so much time there, on the way there, and on the way from there…

The W700 is also easy and effective to paddle, either with a crew of one or two. This is a significant advantage for those who like to fish in shallow water, where motorboats are prevented from going, as well as in water where vegetation abounds, which is also not a good place for motorboats to go. And last but not least, this boat will allow you and your fishing buddy to fish in no-motor zones (NMZ), which typically have a good reputation as bountiful fisheries.  And by the way, the W700 will be equally suitable for kayaking and canoeing, that is propelled with dual-blade (I.E. ‘kayak’) or single-blade (canoe) paddles.

The W700 would be a perfect microskiff for flats fishing, as being both stable and lightweight it would also work great as a poling boat.

Microskiff in white with Spray Shield 640

Boats from the 700 series will be offered in all-white, as well as in three combinations of other colors

 

W700-Green-and-Sand-w-spray-shield-640

 

Sand and Green tandem fishing kayak 640

Read more about this new catamaran fishing boat »

Don’t overpower your fishing kayak, but if you do…

Aside from legal considerations, there are good reasons why you shouldn’t overpower your fishing kayak, and they all boil down to one word: Safety. Simply, overpowering any boat, including a kayak, is hazardous, weather because the extra torque and speed make the boat harder to control to a point where the driver could lose control and capsize it, or because a powerful motor can overstress the part of the hull to which it’s attached (typically the stern), and make it develop cracks that could cause the boat to sink.

When common fishing kayaks are concerned, most online videos that show such a vessel driven while outfitted with a gas outboard motor reveal an overpowered setup – Those SOT kayaks are hard to drive mainly due to poor stability, unsuitable ergonomics and insufficient access to the motor’s controls. In some cases the kayak’s stern is dangerously low to a point  where it’s partially submerged.
As for Wavewalk kayaks, they work perfectly with small outboard motors, but in some cases their owners outfit them with an outboard gas engine that’s too powerful (I.E. exceeds 3 hp), mainly because these boats work better with outboards that feature a long propeller shaft (20″), and such motors are hard to find in the range of small-size motors.

This video demonstrates an ‘overpowered by far’ configuration – A 6 horsepower Tohatsu outboard that fits boats up to 3,000 lbs mounted on a 60 lbs Wavewalk:

Needless to say that such outfit is hard to drive, and requires extreme caution. Inexperienced drivers should not drive overpowered boats, especially such small ones.

motorized-kayak

fisherman-driving-motor-kayak-640

While it is strongly recommended not to overpower your Wavewalk kayak, if you’re determined to do so, here are some tips you may want to remember –
First, make sure the boat is properly outfitted with enough flotation. This may turn out to be critical in case of an accident. Remember that the more powerful the motor the heavier it is, and that in case of an accident, the amount of flotation you use should suffice to keep the boat afloat with the motor attached to it.
Second, make sure the motor mount you use is sturdy enough – Remember that the motor mounts offered by Wavewalk are rated for 2.5 hp to 3 hp, and they won’t withstand the torque generated by more powerful motors. Note that the TMM 20-15 mount featuring in the above video was reinforced with a double mounting plate. Reinforcing the knobs under the deck with wide plates is recommended as well.
While a spray shield isn’t required for driving your motorized Wavewalk on flat water at regular speed, it’s pretty useful when you drive in choppy water and at higher speeds. The same is true for a cockpit cover.

More on this subject »

New speed record for a motorized W fishing kayak

Kenny “One-Shot” Tracy, a W kayak angler from Maryland, broke the speed record for a motorized kayak of the W500 series. He outfitted his W fishing kayak with a 6hp outboard gas motor from Tohatsu.
This powerful engine weighing 57 lbs empty propelled Kenny’s kayak at 13 mph in Chesapeake bay, at 1/3 throttle:

The kayak was stable and its driver stayed dry, and Kenny reported neither tracking nor steering problems.
Before starting his speed tests, Kenny outfitted his W kayak with side flotation.
The motor is mounted on a TMM 20 Wavewalk transom motor mount.

This successful test further reinforces the notion that when motorized, the patented catamaran kayak from Wavewalk can serve as a personal motorboat, or car top microskiff.

The typical fishing kayak is a cluttered barge

This short review of recent kayak design articles highlights some aspects of the common fishing kayak.

The first, and probably most striking thing about the typical SOT, sit-in or hybrid fishing kayak that’s offered in stores or online is its size – It is huge, and consequently heavy and hard for one person to carry and car top, as well as hard to paddle, especially in wind and current.
Those kayaks seem to have crossed the line between a kayak and a boat, or a skiff, since practically speaking they require transportation by trailer. And indeed, some manufacturers already refer to their larger fishing kayak models as boats, not because of their performance or some additional functionality, but due to their size.
Needless to say that this fact alone is evidence that such kayaks defy the purpose of kayak fishing.

The second most striking aspect of those large-size fishing kayaks is the dysfunctional clutter in their cockpit and deck that seem so crowded with fishing accessories and just ‘stuff’ that the angler sitting or attempting to stand in them literally has no room to do so. These objects range in size, from small cup holders to large size lean bars, and their presence in the kayak’s cockpit is not only unnecessary to the angler, it is clearly counterproductive.

The third interesting thing about these larger than life (I.E. too large for real people to fish from in real life) kayaks is the absence of hydrodynamic design in them: They are not even close to conform to basic boat design standards or even to common sense: Not only are they much too wide for their length, which slows them down and makes them track poorly and require a cumbersome rudder – their underside features a variety of design elements that are extremely counterproductive as fare as speed is concerned. Such elements can be multiple scupper holes and molded-in channels, fins, and even a skeg.

Ironically, none of these accessories, systems and design elements offers a real solution to the fundamental problems that the average angler experiences when using them –

These unsolved problems in these common fishing kayaks are:

1.  Poor ergonomics, meaning mainly lack of comfort, early fatigue and back pain, as well as bad bio-mechanical design, which the angler feels as a restricted range of motion in both paddling and fishing. The new beach seat style kayak seats are obviously a botched attempt to address this issue, as foam filled seats failed to do so in the past.

2.  Insufficient stability albeit the fact that these fishing kayaks are extremely wide.

3.  Wetness as a result of the kayak offering too little or no free board, and scupper holes that conduct water upward onto the deck and cockpit, a problem annoying to a point that  manufacturers have to offer scupper plugs…

4.  These kayaks are as wide as canoes and as as sluggish and unfit for paddling in strong wind, waves and other real world factors.

5.  With all the stuff tucked on board a typical SOT, sit-in or hybrid fishing kayak, such craft still scores very low in terms of storage, as one or more hatches address neither the need for enough storage space nor for adequate accessibility to the gear stored inside.

In contrast, the Wavewalk 500 series of twin hull kayaks offers a high level of fishability in all these factors.

References –

More is less in your fishing kayak’s cockpit – Too much stuff and too little fishability

The secrets of the SOT kayak’s underside

THE BARGE – A NEW CLASS OF FISHING KAYAKS