Water + Wind = Fun

What could be more fun than flying a kite or riding a Waverunner? Try both at the same time! That’s the basic idea behind the “Nereus” water craft by designer Mathias Koehler. Powered by none other than Mother Nature herself, this water craft can deliver hours of fuel free fun above and below the water. Steering is managed via foot pedals and the diving function is handled vie the hand grips controlling the pivoting fins at the base. Sailing into the wind is a simple as traditional zig zag tacking. I am still looking for the way to stop that does not include scissors or the wind to die down.

Designer: Mathias Koehler


  • MINIX00 says:

    Wow that is extreme!

  • >I am still looking for the way to stop that does not include scissors or the wind to die down.
    Even thought that might be a joke, it’s a valid question. Traditionally you can slow down, by moving the kite towards the edge of the wind window. There’s also a de-power functionality that works by changing the relative length of the frontlines(those in the center).

  • Nacon says:

    ok that’s a little lame…. just hook up a motor and be done with it.

  • carl says:

    very good.

  • Beautiful! A good inspiration by biomimetism of the “raie manta” 🙂
    See on : http://www.avidedesigner.com

  • Lim says:

    I was kinda excited and impress by the form….But after reading the story behind the idea, i feel this cocnept is trying too hard to have a both cool stylish experience and the green environment issue.

    Looking at the way to stop it, im not sure but i think this is quite simple. Since we have ropes attached to the left and right side of the parachute, why not just to have a hook that able to set loose at one of the rope? I mean, this will created a lose balance of force that is required for the wind to go against the parachute, as there is no force to hold them back.

    The you have somehting like the retractable mouse cable, where the user can then take the parachute back. But i dont think this will be easy…. Alot of engineering issue here….

    And since it is powered by the wind, how do i sail back to the land ?

    • zippyflounder says:

      First its a wing not a parachute (it creates lift) and just like a sailboat it can in theroy go upwind…..but then again the whole concept is unworkable for 9 or 10 reasons.

      • Lim says:

        Dude… Im not talking about the wing. I understand the intention of the designer of trying to use the wing as to dive up and done, which i dont think it will work. But im talking about the point of how to stop the craft.

        As the designer mentioned previously, is cutting away the kite (parachute) is the best way of stopping the craft ?

        By the way, looking at many of you guys comment, still suggestion of putting a motor by Nacon works best haha…

        • Ghazwa says:

          hey…..Lim….MAY I see your works…are u a designer ??? can please send me the link

        • zippyflounder says:

          the tradtional way to stop a kite sailor is by crashing the kite into the water/ground. This used to be a big problem untill new wings came with a inflateable bladder allowing them to float in a “take off” orientation. I need to think about how much thrust its going to take to “dive” this rig, many jet ski’s produce over 700lbs of thrust making flying much more likely than diving if the wing produced that much. It appears most kite sail rigs produce about 300 lbs of thrust in high winds, so there is a real question not only from a power stand point but a force vector one too.

          • Lim says:

            So…again after much debates… Best is this work to be handle by the air force department hahaha….

  • Is this really manifactured, or is it just a project?

  • Evan says:

    Now this watercraft looks very exciting to ride. The best thing, no Fuel!

  • It’s not manufactured, it’s a concept. Stopping, decelerating and even sailing back to the beach, works just like it does with kite boarding and kite boating. I didn’t invent this, I’m just taking advantage of existing “technologies”.

    • zippyflounder says:

      Stick to “designing” as this thing will not work as described for a whole lot of reasons.

    • zippyflounder says:

      I see your also the designer of the rocking chair with a light, here is a clue, ever seen rocking chairs with out armrests….nope me either.

      • Ghazwa says:

        Hey buddy…are u designer…???? can u send me your portfolio Link???

        DAMN theses people really doesnt know what yanko design…is……

        its ABOUT CONCEPT….!!!!!!!!!!

        • Lim says:

          WE know is a concept, but we suggest and criticize so that to bring the idea into another level, perhaps the possibility of manufacturing and market it out.

          Imagine you posted your idea in YANKO and comes with no compliments, i guess that is a pretty sad case…

  • Thank you so much for your meaningful and constructive criticism Mr or Ms Zippyflounder. I will stick to “designing”. I suggest you stick to commenting. In fact I do know quite a lot rocking chairs without armrest: http://www.designboom.com/rocking/winners.html But that again, that’s just the work of “designers”.

    • Lim says:

      Whoa…whole bunch of rocking chair….. Thankz for the web hahaha….

    • zippyflounder says:

      Yes there are a number of rocking chair “designs” shown with out arms, damn few are winners in the world of commerce. The why is simple, rock in your chair, where do you put tyour hands and arms if it has no arm rests, crossed on your lap, hanging down by your sides? Repeat the same experiment with arm rests, much more natural and comfortable, so rocking chairs with out armreasts are giving up confort and useablity for the sake of style, and that is one of the things that seperates sucessful products from “designs”. To answer your other questions, yes i am a product designer with 35 years in harness, have won mutiple awards and have 6 utility patents. I have brought over 40 products from concept to production both for clients and as a entrenpenure. The ability to render ideas that appear real is a powreful tool, and requires that the designer put more thought into the realities of the proposed product. If its just a bit of set dressing, lable it so, and who knows somebody out there might point out the flaws, giving you a chance to either fix the problems or toss it into the waste bin.

  • piment says:

    très beau design… mais je vois mal l’engin naviguer avec un kite

  • Dan Joblin says:

    Hey nice work on the modeling!

    have you thought about using fins at the back to control the up and down maneuvering? this would solve 2 probelms i can see. 1. it would free up your hands to do other things and if you hit a wave and your hands moved on the contol handles you could change the angle of the fins therefore diving the whole think. 2. the kite still needs to be controlled whilst flying and the best way of doing this is with your hands let your feet do the elevation control.
    Very interesting though have you figrued out how many controls you have to have?

    buggy; left/right, up/down, stop

    Kite; left/right power on/power off.

    very keen to see another prototype!! and hear how you get along with this.

    Thanks for showing it.


    • zippyflounder says:

      first off it cannot “dive” as the force vector of the kite (wing) is up along the direction of the lines. The pull of the kite plus the boyancy of the vechile makes a dive impossible. This can be understood with out engineering background you just have to(watch a vid of kite sailors, they are often flying 10’s of feet above the water surface. I wonder if the desiger of this even botherd to do any reaserch whatso ever with kite sailors. Pretty pictures, with out thought are just ………

    • zippyflounder says:

      its not a prototype, is a rendering, because if he had prototyped it he would have found quickly its all ass backwards and upside down.

  • Dan Joblin says:

    hey ya.

    “zippy” when you start off a conversation with “first off……” you come off as a bit if a dick head.
    try to be more constructive!

    I understand a little about kites and kite powered objects and your views are not entirely correct. the beauty of kites is that the vector is not fixed to any direction and thus could provide no upward force and only lateral force. I even heard of a Pro kiter using her kite to pull her with a snorkel and flippers on and diving down for some distance, before coming up, kite attatched.

    another thought is that the buoyancy could easily be controlled or reduced to an effective neutral buoyancy.


    • zippyflounder says:

      the vector will allways be up, as if it is horizontal or down the wing is in the water and no thrust being provided.

  • The Kite provides a force vector up wards, but the vehicle including the driver is pulled down due to gravity. This means there is a resulting vector forwards. Because the Kite is attached a the front, the fins that control diving need to be at the front as well, because otherwise, just the back of the vehicle would be affected, but what I want is the nose to submerge first. So, with the resulting force vector forwards and the fins set in a way that pulls the nose down, the vehicle will dive. Set the fins back to standard and it will rise. I don’t need an engineering background to figure this out. It’s simple logic. I’m currently preparing an extensive press release for certain magazines, including some more images. I’ll link it here is well, once done(sunday/monday). In the mean time, if anyone is interested in further discussing, I suggest emailing me. Thanks a lot for your comments Dan, I appreciate it.

    • zippyflounder says:

      yes you do need a engineering background, as your “simple logic” is flawed. I wish you well, and if you do end up prototyping it please do vid the test runs as that should be very very entertaining.

  • Dan Joblin says:


    “the vector will always be up, as if it is horizontal or down the wing is in the water and no thrust being provided.” zippy quote

    when “KITE SURFING” (the correct term by the way.) the force of the kite will only be directly upwards when the kite is in the zenith, or to say it another way directly over your head. as the kite moves down thought the wind window to the side the direction of force is transfered to the side that the kite is on. This is fact not hearsay! the kite can therefore be held 1mtr off the water and provide approx 95% sideways pull. And on that basis the vector of force that is still pulling up is only approx 5%.

    The weight of an average rider is 75kg. I cant be bothered doing the math but you get the idea.

    This is how kite surfers move forward and even up wind. when they want to get airborne they direct the kite to the zenith or directly above your head and the kite pulls you up converting your speed horizontally into vertical movement.

    when the kite is kept at an angle below 45 degrees perpendicular to the wind the resultant vector force is sideways and the lower the kite the more the side ways vector increases
    vice versa for above 45 degrees.


    this vid i made earlier this year shows what i mean.

    warning looping the kite thought the power zone is for crazy experts only! but the power kick is extreme!

    any more questions regarding kiting feel free to ask

    • zippyflounder says:

      your correct in the lateral force vector, however if the kite is at a 45 degree angle to the water the force at the point of attachemnt to the rider is UP 45 degrees. The simple way to think about this is…its a string being pulled in 3 space, The lower the kite is in relation to the water surface means a higher percentage of that force is/can be used for forward motion, ie 30 degrees off the water would mean that total force “forward” is 70% with 30% being “up”. In the end Mathais did not do nearly enough research before plowing ahead with his wonderful rendering, then tried to BS his way that there was only “one” problem LOL.

  • Dan Joblin says:

    yip agree Zippy, on the 45/45 thing means there is only half the total weight being lifted.

    it brings up an interesting thought for me about design……

    do we as designers only make “pretty pictures” or do we get involved in the engineering side of things to?
    Are we better off letting the professionals do what they trained to do?
    Design is a multidisciplinary subject and that is what interests me personally. where do we fall on this fence.

    • zippyflounder says:

      Any copentent designer must be at least conversent in as many disciplins as possiable, as you mature you put more and more under your belt. This does not stifle design or creativity but enhances it. In my view, designers create real products, artists create works of fancy and whimsy. The latter is much more fun, heck who has not designed a space ship for the starwars universe, but would it work…nope.
      What chaps my ass is people presenting something that looks great, but fails the test of “workable”. Workable can encompass everyting from materials whom their attributes (such as the solar powred cellphone) exceeds reality by such a huge margin that it renders it scifi. Workable also emcompass economic reailty, where a item is proposed that will cost 100-1000% of what that market would likely pay for it.
      The reason this chaps my ass so much, is the research is so easy now, if you dont know ASK. The web has so much expert resouce available its staggering (not like in the old days of phone, fax…yes i am from that era) so to not ask “will it fly, float, work” is just LAZY and UNPROFESSIONAL.

      If you want to draw, model set pieces for the next scifi/action movie great, go to it but dont call yourself a industurial designer, you son or miss are a artist….ID is the world of real, real products, real value, real profit.


  • petnos says:

    Very good. On these days we need this kind of vehicles which are really helpful to the enviroment.

  • jin_woo_han says:

    Great drawing and design~

  • Itzick says:

    I think that is a slick design,

    Please do not get discouraged by the negative dudes, most of them don’t even know how does a kite works.

    About the how to stop thing . a good solution would be you might not remember those retractable lines that some dude was trying to develop, it was an interesting concept but nobody wants to have a bar with a big heavy line winder on it. But since the bar is attached to the vehicle in your design that would not be a problem. Also you could stop the same way you stop with a board which is edging against the kite and if the wind is to strong you stop by going completely downwind towards the kite just like you do on a buggy.
    Another idea would be to have a little electric motor to move around when you don’t have kite.

    There have been other designs of other vehicles that have look like a catamaran and you seat in the center but I really see much more potential in your design.

    Have you actually built any prototypes??

    Good winds for ya ,

    Keep it up

  • DJog says:

    I’m amazed at how much coverage this styling fantasy has received – It just simply wouldn’t work and some basic research into traction kites or even the principles of regular sailing – of which kitesurfing is another form – would have shown that.

    If it’s meant to be just an exercise in styling then fine but it’s no more a piece of real design than something from Star wars.

  • Donovan says:

    I might have a solution as to how to slow ( maybe not stop) the nereus if you ever get to building it. If you put fins in the rear that are controlled by your feet, you can dip them into the water and the back end of the craft would foillow. The deeper it goes, the more drag is created, and the slower it goes. Probably won’t stop it but you could certainly go slow enough to pull in to where ever you launched from. And to get going again, pull the fins out of the water. Just a thought but it might work.

    Good luck with the design, I think it will work, even if most of these people don’t

    • Djog says:

      it wont work, dont waste your time on it.

    • valerie says:

      If I said I’d thought the best way to slow a car would be to throw an anchor out the back you’d ask why not just take the foot off accelerator or use the brake and assume that I knew nothing about how cars work.. Well this design and suggestions like those above show a similar lack of understanding about how sail craft operate so suggestions like adding braking fins are as daft as the car anchor idea.

      Besides, the basic problem with this thing is not stopping it but getting it moving in the first place. the shape of it and the fact that the riders legs are submerged in the water creates a massive amount of drag. You’d have to use a massive kite to move it, probably double the size you might use if kiteboarding which creates big risks for launching and landing, control in gusts and accidental miscontrol becoming much more serious.

      So lets say you’ve done that and you get moving. Kite sailing involves the kite generating pulling force perpendicular to the canopy so the kite has to be placed at the side of the vessel and resistance to the lateral component of its pulling force allows the forward component to pull the craft forward – generally across the wind direction. How does the rider stop the craft just being pulled over sideways? Theres a good reason why kite boats tend to be catamarans – a simple google search would have revealed that.

      It also makes the false assumption that the kite is steered like some kind of airborne powerboat. point it where you want to go and the boat follws Wrong, Steering allows the kite to be placed in the air to generate the general direction of the pull the rider needs relative to the wind, steering the vessel is accomplished by directing the board or using a rudder if on a kite boat.

      anyway, its a silly idea. there you go.

  • Robert Frost says:


    No, but really, that’s fking awesome. I want two of them!

  • Jeff says:

    Thats cool looking and all but I mean…I guess testing is not a prerequisite for validating design anymore…sad.

  • stephen russell says:

    Great for use in HI ,FL, CA, PR & Caribbean.
    Be Fun 2 own & rent, Radical.
    Produce this, & add Buddy Seat too.
    Way 2 Cool

  • South_44 says:

    With regards to stopping, have you considered looking at the kite, perhaps creating a “vent valve” on the lowerside of the aerofoil?
    Allowing the kite to become less aerodynamically sound?
    This would allow the vehicle to slow and maintain the kite in the air for a period of time sufficient to reel it in?
    This would result in a unique kite design and perhaps a more exclusive and specific spectrum when marketing to possible backers. Knowing that all the products to be used with this product are produced exclusively by you.
    If you have any more questions about the “vent valve” let me know, its easy to adapt a normal kite design and requires no heavy parts so will not comprimise the weight of the kite.
    Let me know what you thing.

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