MOTOR KAYAK

S4 motor kayak beached in Hawaii

Updated August 5, 2024

High Performance Motor Kayaks

What is a Kayak?

Definition: Officially, a kayak is a small, lightweight, human-powered vessel designed to be propelled with a dual-blade paddle (kayak paddle), by one or two paddlers seated in the recumbent (L) posture.

What is a Motor Kayak?

Definition: Officially, a kayak powered by a motor up to 3 HP is a motorized kayak. A vessel rated for more than 3 HP is no longer a kayak, it is classified a boat. More reading: Motor Power Rating For Canoes, Kayaks, and Small Boats

“Kayak” Powered By a 9.8 HP Outboard Motor?

No. If a vessel can be successfully and safely powered by a motor bigger than 3 HP, and it’s rated for more than 3 HP, it is not a kayak. In the case of the S4 Microskiff, although it works perfectly as a human-powered vessel, and it can be comfortably propelled with kayak paddles, it is classified as a multi-hull boat, since it is rated for 6 HP motors.

What is a High Performance Motor Kayak?

Definition: A High Performance Motor Kayak is both seaworthy and powered by an outboard gas motor – Wavewalk’s W720 is a high performance, catamaran motor kayak, and Wavewalk’s S4 is a ultralight cartop catamaran microskiff that works perfectly as high performance motor kayak.
In contrast, SOT and sit-in kayaks are not suitable for powerful motors, due to their form, insufficient stability, and ergonomic issues that prevent both effective driving and safe operation of the motor. What might seem to work in a YouTube video doesn’t work in the real world.
Electric motors are weak, and they have a restricted range, which is why they work mostly for trolling on flat water over short distances, and for assisted paddling. This said, a kayak with such a weak motor is still safer and more convenient to use than a kayak without one.

Wavewalk’s S4 as the top Motor Kayak

The patented S4 is the only small boat that you can paddle conveniently as a kayak or a canoe, solo and in tandem. This is made possible by the fact that the S4 is just 38″ wide, and its cockpit features sloping sides that allow paddles to move alongside the cockpit in an undisturbed manner. This patented catamaran cartop microskiff drafts so little that it outperforms most kayaks and all microskiffs when fishing shallow water is concerned. However, being a true catamaran, and featuring a Personal Watercraft style saddle-seat, the S4 is also a seaworthy portable boat for offshore fishing.

Weighing just 100 lbs, and designed for both effective paddling and easy driving (seated and standing), the S4 works great as a solo and tandem kayak, with a motor and without one. As such, it beats all other kayaks out there in terms of stability, comfort, seaworthiness, storage, versatility and mobility. The S4’s unique built and features make it more functional in fishing terms, compared to fishing kayaks as well as  other small microskiffs.

WAVEWALK S4 MICROSKIFF ANIMATION 2024

How the S4 is designed:

The S4 is classified as a multihull boat, and it’s rated for motors up to 6 HP.

More about the S4 »
The W720 Catamaran Kayak Skiff: Solo & tandem catamaran kayak that works perfectly with an outboard gas motor

If you actually need a trailer-free, ultra-lightweight, two-person catamaran kayak that’s easier to paddle than other kayaks, and is rated for outboard gas motors up to 3 HP, checkout our W720 »

W700 kayak skiff animation
W720 kayak skiff in various modes and usages

We classify the patented W720 as a one or two-person touring and fishing catamaran kayak skiff. The W720 offers enough passenger space, storage room and load capacity for one or two anglers, and its stability is on par with the stability offered by good size Jon boats and microskiffs.
Common SOT and Sit-in fishing kayaks, including the biggest and widest ones, don’t provide this much stability because of their monohull design, which is the primary reason why they cannot be driven with powerful outboard gas motors.
However, Wavewalk’s W720 kayak skiff is just 31″ wide, and it is both much easier to paddle and more comfortable than SOT and Sit-In fishing kayaks are.

Electric motors are weak in comparison to outboard gas motors. Some very big SOT and sit-in kayaks can take an electric motor, but they cannot work properly with a powerful outboard gas engine. However, the W720 works perfectly with an outboard gas motor of up to 3 HP.

Why Motorize Your Kayak?

A motor adds to your kayak’s speed and range of operation. In certain situations, this can make the difference between being able to come back home, and staying out on the water, or beaching far from where you had launched from. That is to say that a motor can add an element of safety to your kayak fishing or touring experience.
Another consideration is that a motor can make life easier, if you don’t feel like paddling, or in case you’re not capable of paddling where you want to go.
If you’re fishing from a kayak, a motor can be useful for trolling, and for quickly skipping from one fishing spot to another.

Read more about Why Motorize a Kayak » 

Electric Trolling Motor or Outboard Gas Engine?

If you don’t own a Wavewalk kayak, you may as well skip this section, since other kayaks are not suitable for outboard gas engines, and they can accommodate only weaker, electric motor systems that are commonly know as trolling motors, because they typically involve going at low speed, and generally on flat water.
However, if you own a W500 kayak and you’re looking to motorize it, you’re facing the problem of choosing between an electric power system, and an outboard gas engine.
Before going further, we’d like to clarify a number of things about outboard gas engines:
First of all, we don’t recommend using an outboard motor that’s rated above 3 hp with a Wavewalk kayak from the 500 series, simply because there’s no need for more, in our opinion, and we think that a stronger motor might overpower the kayak, which is hazardous.
Second, when we refer to outboard gas engines, we mean 4-Cycle (4 stroke) motors that are cleaner, quieter, and easier to operate than the old, 2 stroke motors that require mixing oil in the fuel.
Third, we recommend using an outboard gas engine with a 20″ (long) shaft, and not a 15″ (short) shaft.

What are the drawbacks of outboard gas engines?

The most obvious is that they are noisy, while electric motors are quiet.
As far as fumes and ease of operation, the new 4-cycle motors are as clean and easy to operate as electric motors are: No fumes, no need to mix oil in the fuel, and starting them is easy.
Weight: The 2hp 4-cycle Honda outboard gas engine weighs 28lbs. It’s heavier than some small or expensive electric motor systems, but considerably lighter than others that can weigh up to 80lbs. In any case, at this weight you can lift the propeller out of the water and paddle your W500 without feeling much of a difference in performance. You can drag the kayak on the beach, and you can even car top it.
Price wise, a new 4-cycle outboard gas engine can cost between $1,000 and $2,500, while an electric motor system can cost between $250 and $1,500.
Maintenance: Outboard gas engines require some maintenance while electric motor systems are almost maintenance free, but the new, 4-cycle motors are much easier to maintain than the old 2-cycle ones, so this is not necessarily a big disadvantage.
Some areas are restricted to motorboats, but not to ones that are powered by electric motors.

What are the drawbacks of electric trolling motors?

There’s a much broader choice of electric trolling motor systems on the market today, which means there are numerous advantages and disadvantages to consider.
The most common disadvantage in electric trolling motors is their limited range and speed, and the two are closely linked to each other. Gas motors offer unlimited mileage at high speed, since you can take plenty of extra fuel on board in a can. This is not the case with electric systems that depend on batteries that are either very heavy (too heavy to carry more than one on board at a time), or very expensive. Going at full speed with an electric trolling motor, even a weak one (30-40 lbs thrust) can drain your battery pretty quickly, even if it’s an expensive high-tech battery. This leaves you with a choice of a weaker electric motor, and consequently reduced speed.
When evaluating the potential of an electric trolling motor, you need to remember that going at full power instead of half power would never double your speed (in fact, in some cases the effect of adding power may be hard to notice…) but it would surely drain your battery at half time. You also need to bear in mind that both water and weather conditions often require using more than a fraction of your electric motor systems’ capacity, because the real world is not an ideal one. Knowing this, you need to view electric trolling motors data as representing perfect world situations that have partial, or little relevance to real-life situations in which you could, and eventually would find yourself on the water.
Weight: A standard, deep cycle marine battery can weigh between 40-60lbs. That’s a lot for a small, car top boat such as the W500 kayak. On top of this, the motor itself adds weight, so the entire electric trolling motor system can weigh more than the kayak itself, which is counter productive and problematic. For example: If your heavy, deep cycle marine battery runs out of juice far from your starting point, you’d need to paddle your kayak back with an additional heavy load on board – It’s a point worth consideration, especially if you imagine going against a tidal  current, and/or strong wind, while being tired after a long kayak fishing or touring trip.
Price: A battery, cheap electric motor and charger can be yours for less than $250. This is a good deal, but you’ll pay the price in high weight and low speed. At the other end of the spectrum, a computerized electric trolling motor system with integrated GPS would cost you over $1,500, and although it will be lighter than an outboard gas engine, it would still offer less speed and a smaller range of travel.
Maintenance: While electric motors are practically maintenance free, their batteries need recharging, which takes both time and a power outlet that might not always be available to you.

If you’re thinking about powering your S4 Microskiff of W720 kayak-skiff with an electric motor instead of a gas outboard motor, we recommend a model that has between 40-55 lbs of thrust, powered by a 12 Volts battery, or batteries.

Thrust, Horsepower (HP) and Kilowatts (KW)

People outfit their W720 kayaks with electric trolling motors ranging between 25-70 lbs thrust, with the typical range being 30-50 lbs thrust.

For the W720 we recommend outboard motors up to 3 HP. Some clients drive their S4 Microskiff with motors up to 10 HP, but we recommend not to exceed 6 HP. The motors that people use for their S4 range between 3.5 HP and 6 HP. Less than 3.5 HP for this microskiff would be under powered.

We recommend not to overpower your Wavewalk, as doing so may be hazardous, especially for inexperience users.

Kilowatts and Horsepower

1 KW = 1.34 HP

1 HP = 0.745 KW

This basic information could be useful when you read electric motor specs…

Conclusion? -Between outboard gas engines and electric trolling motors there is no winner or loser, and it’s up to you to systematically weigh the pros and cons, relatively to your touring, camping and fishing needs, as well as your carrying capabilities, and last but not least – your budget.

Tip I: If you’re thinking long trips, camping, moving water and tandem – think outboard gas engine. If you’re thinking short trips, flat water and lighter loads, think electric trolling motor. Needless to say that more power equals more fun, but too much speed could be hazardous.

Tip II: Whether you choose to outfit your kayak with an electric motor or a gas outboard engine, if you’re planning to take your Wavewalk kayak in saltwater, make sure the motor is rated for saltwater.

What is the legal power limit for kayaks?

The US Coast Guard (USCG) regulates the kayak and boat market, and it set limits for the power allowed for motors used with kayaks and canoes. First, you need to determine whether your vessel is a kayak, a canoe, or a boat, and once you do this, see that the motor you choose for it does not exceed the legal power limit. This power limit is defined in horsepower (HP) for gas outboard motors, and in Kilowatts (KW) for electric motors. Read more about the definition of a kayak and the max power allowed for kayaks »

Wavewalk classifies the W720 catamaran as a kayak, and rates it for a motor up to 3 HP.
Technically speaking, the S4 is a mulithull boat, and as such it is not subject to mandatory power limitations for monohull boats of its size. Still, out of caution and practical considerations, Wavewalk rates the S4 for maximum 6 HP.

Additional reading: Understanding Thrust vs. Horsepower »

15″ Short (S) Propeller Shaft or 20″ Long (L) Shaft?

20″ Long (L) propeller shaft outboard motors fit both the W720 and S4 perfectly, and these are the motors that we recommend using.
As for short (typically 15″, up to 18″) shaft motors, they don’t perform well with Wavewalk kayaks and boats (the problem is called Ventilation), and we do not recommend using them. This is true both for electric and gas motors.

The 20″ distance is measured from the inner top side of the motor’s clamp bracket to the horizontal ventilation plate located above the propeller. More info on how to measure the outboard propeller’s shaft length »

Any motor, whether electric or gas, whose propeller shaft is shorter than 20″ is not recommended for use with Wavewalk® kayaks or portable boats.

Overpowering your motorized fishing kayak

Overpowering a kayak or a boat can be hazardous, and result in accidents, which is why we recommend not to do it. Overpowering a boat is illegal in some states.

More reading: Overpowering the W720 Kayak Skiff »

More reading: How much horsepower for my S4’s outboard motor? »

Important SAFETY ADVICE

Never operate your motorized kayak without its stop switch (“kill-switch”) attached with a lanyard to your arm or your belt.

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3 thoughts on “MOTOR KAYAK”

  1. Pyt Rotary says:

    Best Motorization for fishing

    After playing with kayak for 5 years in various body of water (rivers, shallow rivers, lakes, swamps, big lakes: Ontario) I did reach these conclusion
    IMHO – for fishing the best motorization is the electric motor at 24V with Digital Maximizer
    Advantages:
    1) Silent
    2) No smoker
    3) Low maintenance
    4) The Wavewalk is stable but once you deploy the electric motor down is becoming rock solid stable.
    I am having fun on the big lake when I see big boats with V profile having sway (rocking side to side like hell) and my kayak with the trolling motor deployed is stable like a rock (no sway).
    5) After trying over 5 trolling motors I did finally settle for 24V with 70Lb thrust. If I have the chance I will go for 100Lb.
    There are some important advantages of 24V in Wavewalk.
    a) You need two batteries that will have the weight nice distributed in the twin hull for balance in front.
    b) 24V is more efficient than 12V (draws less Amps) therefore you don’t need heavy batteries. Two batteries of 22Ah (6kg each) are sufficient for over 24h or continuous trolling at 3km/h or 1.5mph
    c) 24V does not need thick wires as 12V (less Amps draw)
    d) 24V motor has a heavier coil than 12V (12V has 11Kg, 24V has 15Kg). The center of gravity moves low, than means more stability. Gas motor raise the center of gravity, not ideal.

    The only drawback for electric is that it does not have the power of the gas.
    But with 24V I can cruise for more than 24 hours on penny in comparison with gas cost.
    Plus the torque is instant. And for trolling with 1.5-2mph there is plenty of thrust. You just need to dial around 15-20% of the throttle.
    At full throttle the speed is 8Km/h.

    I did preferred a simple mount for the motor, I just use a 2×4 regular wood from Home Depot.
    There are many time when I don’t need the motor on the kayak, therefore simplicity is the best.

    Last performance of my motorized kayak was on 29 August trolling around 15 boats on Lake Ontario 3 km offshore at night chasing salmon.
    Imagine how much gas those guzzler burn and in top of that with a slick Wavewalk I can dance around those boats that steer like snails.
    Actually after 10PM there were no boats around just me and another few kayakers in [fins and push-pedal driven kayaks] that were tired of pedaling and were close to shore.
    A [fins and push-pedal driven] kayaker can’t match the advantages of a Wavewalk electric motorized, pedaling for hours is not easy.
    The best sprint on water is electric (instant torque at fingers tips).

    Have fun, tight lines.

  2. Thanks Pyt,

    70 lbs thrust is very powerful for an electric motor for such a small craft. I’m sure you can go fast with it!
    Using two smaller-size batteries instead of a single large size one is also what we recommend, since you can place each smaller battery at the bottom of each hull, and thus have them act as ballast, I.E. improve the kayak’s stability, while a big and heavy battery placed in a higher location would be counterproductive in stability terms.

    Yoav

  3. Pyt Rotary says:

    The feeling of the 24V throttle is like driving a motorcycle.
    For sharp turns I have to lean over.
    You don’t need bigger batteries at 24V. The draw at 25% throttle is 500mA that is more than 40 hours of trolling non stop for a 20Ah batteries (6kg) for 3km/h in none or low wind.
    I repeat there is no need for heavy batteries as long you don’t battle heavy winds (>20km/h) and you just want to fish/trolling. I have two set of batteries.
    One set of 22Ah(6kg each) and one set of 35AH(12kg each). For regular fishing trips where the trip is less than 20km 24V with small batteries is just fine.

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