Weekender/Picnic Vessel, Power and/or Sailing Catamaran

Discussion in 'Boat Design' started by brian eiland, Jul 16, 2010.

  1. svmegatron
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    svmegatron Junior Member

    That looks *really* cool. I am not sure about building the entire boat myself, and I'm sort of hoping for something smaller (I know the M36 is not at all smaller, but my ideal size is 26-28 feet) but a kit makes it seem less daunting.

    Right now the top spot on the "boats I'd have to build from scratch" list (vs. the "boats that might be able to be converted" that I started this thread with) is Richard Woods' Skoota 26 (seen at the bottom of this page: http://www.sailingcatamarans.com/skootas.htm ) I've corresponded with Mr. Woods and I ABSOLUTELY LOVE the design, but as I mentioned, the idea of building (or paying someone else to build) the entire boat from scratch is pretty daunting.
     
  2. brian eiland
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    brian eiland Senior Member

    http://www.gunboat.com/55-gallery.php
     

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  3. brian eiland
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    brian eiland Senior Member

    Shuttleworth day-cat

    Just happened across this Shuttleworth version of a day-charter cat,...outboard powered as well
     

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  4. brian eiland
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    brian eiland Senior Member

    I was doing a little clean-up recently and discovered a few more 'interior photos' of that Thai cat that I took on a subsequent trip. I still really like this 'open concept'.
     

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  5. brian eiland
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    brian eiland Senior Member

  6. brian eiland
    Joined: Jun 2002
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    brian eiland Senior Member

    Too bad these fellows at Gunboat ran into such financial problems.They were producing a nice product.
    https://www.youtube.com/watch?v=cveZ9UsxMt0

    You might find it interesting that I thought they were inspired by a few such themes before them...
    http://www.boatdesign.net/forums/powerboats/weekender-picnic-powercat-33751.html#post495002

    http://www.boatdesign.net/forums/powerboats/weekender-picnic-powercat-33751.html

    If you look closely you will discover that the Thai charter cat has openings all around the cabin area,.... they are just covered in canvas at this this stage due to the strong sun light in Thailand.

    Something along this idea on the Thai 'picnic cat 'is one suggestion I might have given Jimmy Buffett for his new fun boat,...as opposed to that monohull mess they sold him on !! Just add a little sailing rig to that Thai picnic cat
     
  7. Phlames
    Joined: May 2017
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    Phlames Junior Member

    This is my first time posting so be gentle with me. The idea of a weekend/picnic boat motivated me to design and build this 35' power catamaran - I think of it more as a toy for wealthy people to display at their private jetty outside their canal development McMansion although it has proved to be capable of coastal cruising.
    The boat is powered by twin 90 HP outboards, does 25 knots and gets 13 l/hr @ 13 knots cruise. Sleeps six, two in a queen sized double and has an all electric fit out (no gas). The half load displacement is about 3.6 tonnes and the 15' beam is the max. allowed at most local marinas for a single berth.
    The boat handles well, is very comfortable with full interior foam backed marine vinyl, carpets,etc. and is (in my opinion) good looking. With a bridge deck clearance of 600mm it is not meant for open ocean work and suffers the usual catamaran trade-off between load and performance.
    I would be interested in any thoughts about my creation.
    IMG_1238.JPG alt.1212.jpg 8499mod.jpg
     
  8. Mr Efficiency
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    Mr Efficiency Senior Member

  9. brian eiland
    Joined: Jun 2002
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    Location: St Augustine Fl, Thailand

    brian eiland Senior Member

    Nice looking design. Perhaps share some more details?....and interior layout, photos etc.
    Welcome to the forums.
     
  10. Phlames
    Joined: May 2017
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    Phlames Junior Member

    The empty weight of the boat is just less than 3 tonnes. With 3 pax, 200 l of fuel and half full fresh and waste tanks the half load displacement is about 3.6 tonnes. The hulls are 12 mm WRC, the cabin, seats and some interior items are 15 mm divinycell foam, the three box beams are ply/oregon framing and the doors/bridge deck floor are polycore - all with epoxy and glass.
    The interior features two helm, a three place seat and two single seats with seating for six in the cockpit. On this level is also an expandable table, three 'horizontal benches' for putting stuff and a cupboard large enough to contain a future air conditioning unit.
    The starboard lower level in the hull contains a queen size double at the rear, a changing/dressing area, ice box/storage, hanging locker,upper large single berth and lower single berth with a fold up work table. The port lower hull level contains an electric toilet, shower, hand basin in the 'bathroom area and a galley amidships with sink, microwave, induction cook top and lots of storage. Further forward is a mirror image berth layout the same as the starboard hull.
    Apart from the usual instrumentation the boat has electronic engine controls, hydraulic steering, 3 kW inverter, 4 kW isolation transformer, full 240V AC and 12V DC systems.
    All designs are a compromise and with this boat the decision was made to do away with 'sideboards' so that the only access to the fore deck area is via the electric actuated front 'door'. This allows for a much roomier feel to the cabin and lower levels and also gives better standing headroom in the hull areas. Cabin headroom is about 1.93 m. and there is a skylight panel in the cabin roof.
    I hope this gives some more information together with a couple of photos below.
    And thank you for your kind comments.
     

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  11. Mr Efficiency
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    Mr Efficiency Senior Member

    The slenderness of the bows does not cause hobby-horsing ?
     
  12. brian eiland
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    brian eiland Senior Member

    I know you were seeking to have the props on those outboards as far down in the water as possible to reduce their cavitation potential,...but do you realize how much extra drag those lower units create if they are always deployed thusly?
    [​IMG]

    The reason a lot of racing powerboats utilize 'jack plates' to get the lower units out of the water as much as is possible on occasions that permit it. A variation on that theme could reduce your fuel bill significantly.
     
  13. Phlames
    Joined: May 2017
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    Phlames Junior Member

    I find that weight distribution is more critical to this boats' fore and aft stability. The fuel load in the photos was about 60 l or about one seventh of maximum (400+ l) and the tanks are located forward of the main beam meaning a slightly bow 'out' stance underway. With 6 pax on another day and 25 knots wind against current giving a 4' short chop and a light fuel load there were two instances of bow burying at 14 knots and this was as a result of hobby-horsing. The photos don't show the vertical profile of the bows but they actually are wider at the waterline than at the top, similar to the sailing Nacra cats.
     
  14. Phlames
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    Phlames Junior Member

    You may be correct wrt outboard height. At present the cavitation plates of the engines are level with the hull bottoms. Another factor is that this is not a planing hull but a displacement hull design with flat runs aft to the props creating the infamous 'suck' trough at hull exit. I think the fuel consumption at present is excellent and the envy of many I have spoken with.
     

  15. Mr Efficiency
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    Mr Efficiency Senior Member

    I doubt jacking plates would be beneficial, you would lose prop disc area raising the props, reduce thrust and gain very little from a lessening of appendage drag, even assuming the props don't let go. The boat is too slow to get any value from it.
     
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