High Speed Kayak

Discussion in 'Boat Design' started by fluffysheap, Aug 25, 2008.

  1. fluffysheap
    Joined: Aug 2008
    Posts: 2
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    Location: Seattle, WA

    fluffysheap New Member

    My workplace is moving to the shore of a lake. It so happens that I live on the opposite shore of said lake. This has caused me to think of a so-crazy-it-might-work idea and I was hoping for opinions...

    I would like to motorize a kayak and use it for commuting. For this to work it would need the following performance:
    * About 10 miles range
    * About 25 mph speed
    * Small and light enough that I can carry/drag it for a block.

    My plan:
    1) Buy a Flyak
    2) Attach Minnkota trolling motor or weed whacker motor
    3) Go real fast
    4) Try not to kill myself

    Your job:
    1) Tell me why this is insane
    2) See #1 :)
  2. Guest625101138

    Guest625101138 Previous Member

    How far have you got to travel and what weather conditions can you expect? What is the maximum fetch distance for waves to build up? Weed?

    You could halve the weight if it did not have the engine.

    Something like the Cadence will do 6mph with reasonable ease. A purpose built boat could do it faster under pedal power and be similar weight to the flyak. (Are flyaks being sold - how much?)

    Flyak is a twitchy machine and the more weight you add the more power it will need to fly. I expect the paddler hits about 1kW when he is getting the thing to lift so adding the weight of an engine will mean 1HP will be borderline to get it flying. The batteries will probably kill the MinnKota. The motors produce under 0.5kW. You would be better going for an outrunner type motor, a lithium battery and special prop.

    A good displacement hull could get 12mph with a lightweight 1HP motor or 8mph with a moderately fit human engine. The human engine offers a lot of benefits like not having to worry about fuel. On the other hand it is not something you would do in a suit and tie. Would avoid any need to ever go to a gym. You would be the most relaxed worker in the place. A constant high on endorphins without the angst of traffic. Pedal boating is the best way to exercise I have found.

    So provide a few more parameters on what the expanse of water is like and see what else might come up.

    Rick W.
  3. Guest625101138

    Guest625101138 Previous Member

    I can answer one of the questions above myself. Price of flyak is EUR1900 plus transport plus applicable tax. This includes a EUR300 training package so it would seem quite a skill to master. Not yet being delivered.

    Can you imagine someone in a suit trying to mount something sitting in the water that is 500mm beam with a semi-circular hull!!! Then flogging crap out of the pull cord on a weed wacker engine while staying upright. Would be an interesting sight. Maybe even a candidate for funniest home videos.

    Don't think it is insane just bound to be funny - maybe also wet and cold.

    Rick W.
  4. Knut Sand
    Joined: Apr 2003
    Posts: 471
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    Location: Kristiansand, Norway

    Knut Sand Senior Member

    Did a google for flyyak, as it was new to me, well it did seem the name was new for me, not the concept. Found out that the foils were far smaller than I had expected too...

    (This is maybe a bit off the track, but can you include the wind in this consideration?
    :D :D )
  5. Guest625101138

    Guest625101138 Previous Member

    Did you see the windsurfer in the background? Sort of verifies that planing is as good or better than foiling if you use a low aspect foil. Planing might be harder on the skeleton though.

  6. alexlebrit
    Joined: Aug 2006
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    Location: France - Bourbriac

    alexlebrit Senior Member

    Question - why do you have to drag the thing for a block and at which end are you dragging it - home to shore, shore to office or both? Is it not possible to moor? Is it ten miles each way or ten miles all together? And then all the other questions thrown in too.

    Not that I have any answers yet, but, I just wanted more details.
  7. RivrLivn
    Joined: Nov 2007
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    Location: US

    RivrLivn Junior Member

  8. rwatson
    Joined: Aug 2007
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    Location: Tasmania,Australia

    rwatson Senior Member

    Wow - that Mokai is a great little concept. It woudl beat trying to balance a Flyak while the motor gets up to speed.

    Actually, a Flyak with an outrigger or two might cut it - through it is very sensitive to weight and might require redesign of the foils
  9. kengrome
    Joined: Jul 2006
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    Location: Gulf Coast USA

    kengrome Senior Member

    You'd probably get to work directly across the lake at 30 mph in this baby.

    It's 2 feet wide, 24 feet long, and powered by a Honda GX200 engine with 1:1 gear ratio, direct drive via cone clutch and a 6 inch two-blade stainless steel propeller.

    The whole thing wouldn't cost more than $1000 to build in the USA using the best quality plywood you can lay your hands on. I think I can build one here in the Philippines for about $300 complete -- and this even includes the labor over here!

    You might want a spray deflector on choppy days ...


    Attached Files:

  10. Knut Sand
    Joined: Apr 2003
    Posts: 471
    Likes: 30, Points: 28, Legacy Rep: 451
    Location: Kristiansand, Norway

    Knut Sand Senior Member

    I didn't notice that one, the fact that its actually catching up, going faster....

    Rough on the skeleton... Think of how it will feel when you're flipping over, feets securely placed in the straps on the board.... on that foil sailboard.
  11. Village_Idiot
    Joined: Oct 2007
    Posts: 382
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    Location: USA

    Village_Idiot Senior Member

    Maybe check out the Gheenoe. http://www.gheenoe.net/index.html
    Electric motor won't get you 25mph, small 2-str. outboard will. Not much more weight than the set of batteries needed to power the electric. You can build or buy a canoe dolly to wheel it one block.

  12. Jack Daniels Eq
    Joined: Aug 2008
    Posts: 50
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    Location: Phuket

    Jack Daniels Eq Shockwave

    Thats nuts
    How do normal folk do this ?
    Wait for winter, skate over
    Build a cannon either side
    Keep ya day job
    Have fun - drink more
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