catamaran boat plans

Discussion in 'Boat Design' started by garrybull, Feb 17, 2013.

  1. garrybull
    Joined: Nov 2010
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    Location: portsmouth england

    garrybull Senior Member

    hi guys.

    do any of you know where i can get hold of some plans to build a 6-7 mtr outboard powered cat.

    needs to be able to cruise at around 22-25knots.

    i want to build this out of ply and then mould it so i can make myself a grp one.

    i am in the process of trying to buy a set of 6.5 mtr cat moulds but the seller is now not answering his phone or replying to my emails hence why im now looking for plans to build one from scratch.

    im not worried about internal finish etc as i only want hull plans.

    im looking for some thing that has a good height out of the water and good clearance through the centre of both hulls.

    any info etc is much appreciated.
     
  2. Richard Woods
    Joined: Jun 2006
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    Location: UK, USA and Canada

    Richard Woods Woods Designs

  3. garrybull
    Joined: Nov 2010
    Posts: 508
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    Location: portsmouth england

    garrybull Senior Member

    thanks for the links mate

    i have seen the powercats before.

    what im after is detailed plans to make a wooden cat hull with all measurements for cutting up the timbers etc to size to allow me to clad it with ply.

    im even thinking of making just the one hull on its own and use that to make 2 hull and then make the bridge deck through the centre.
     
  4. Richard Woods
    Joined: Jun 2006
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    Location: UK, USA and Canada

    Richard Woods Woods Designs

    well you'd get detailed plans and photo manual with my Skoota 20 plans.

    I suggest you email me direct to discuss things further, possibly you want just the hulls and not the cabin

    Richard Woods of Woods Designs

    woodsdesignsATgmail.com
     
  5. garrybull
    Joined: Nov 2010
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    Location: portsmouth england

    garrybull Senior Member

    the cat that you have is not really the type im after.

    do a search on here and look up carat 21.

    thats the style i want to make as its a perfect fishing platform.

    i want to run twin outboards on pods out the back to maximise deck space.

    will send you a pm tomorrow and see if you do any other designs.
     
  6. Mr Efficiency
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    Location: Australia

    Mr Efficiency Senior Member

    I am not a big fan of podded cats in that size range. The obvious attraction is greater internal space, and you may get some greater efficiency from the engine set-back, but it is all downhill after that. You get a boat that is more inclined to porpoise, and I think to a greater extent than podded monohulls, for two reasons, 1. Cats are not as stiff in pitch with the narrow effective waterline, and 2. The centre of dynamic lift is further forward in a cat ( the leading edge being more toward the bow than a monohull) which exacerbates the bow-up attitude. The usual antidote is wide chine flats, without which you would have a real hobby-horse. Overall I think the ride is better without pods, but it is the usual story of compromise, if space is job #1, podded it is.
     
  7. garrybull
    Joined: Nov 2010
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    Location: portsmouth england

    garrybull Senior Member

    im not 100% certain on the pods yet.

    once i get the hull plug built then i'll be able to see what sort of deck space there is.

    if there is enough space then i won't go for the pods. i'll make outboards fit directly on to the transom.

    i like a lot of room on my boats and that why i was going to go for the pods.

    i have now agreed a price for a 6.5 mtr cat hull/plug which im going to modify slightly to make it how i want it.

    im hoping to pick it up saturday or sunday.
     

  8. Mr Efficiency
    Joined: Oct 2010
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    Location: Australia

    Mr Efficiency Senior Member

    Even transom mounted outboards don't want to be too heavy, as e.g. some four-strokes. I am pretty well confirmed in the view that they don't like too much weight back there, in a larger boat say 8-9m it would be less of an issue as engine weight is a lesser % of the total weight. Catamarans of all types are more sensitive than monos to lengthwise weight distribution, and its effect on running attitude.
     
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