The Ideal 18ft Daysailer

Discussion in 'Sailboats' started by Paulo.AS, Sep 20, 2008.

  1. Paulo.AS
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    Paulo.AS Junior Member

    Hello to all,

    I'd like to have the input from all those interested about the following parameters:

    Sailpan
    Fin keel or daggerboard
    Crew number

    The goal is to design a 18 footer for daysailing and the eventual handicap regatta.

    Thanks to all
     
  2. BHOFM
    Joined: Jun 2008
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    BHOFM Senior Member

    Trailer-able, it should be a dagger board, ballasted,
    the boat should be self righting,

    Crew? Any 18 will be single handed capable, max 6
    comfortable 4.

    Nice wide side decks to keep it dry in a knock down.
    Medium beam for good speed.

    Are you set on an 18? Cost of construction, a 20 won't
    be much more? Price seems to jump every 4' more
    than 2'!

    There are some nice 20' racing scows if you like the older
    look?

    I like the look of the scows!
     
  3. Paulo.AS
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    Paulo.AS Junior Member

    BHOFM,

    Thanks for the input. And yes I'm bound to the 18' dimension.

    About the saiplan I was thinking a squarehead main, jib and assimetric spi/gennaker on a sprit. I want this baby to be mean and fast, a wet and thrilling ride.
     
  4. RHough
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    RHough Retro Dude

    "mean and fast, a wet and thrilling ride" do not mix with "Daysailer"

    What you describe with "mean and fast, a wet and thrilling ride" is just another hot rod racing boat. Buy a 18 foot skiff. ;)
     
  5. Doug Lord

    Doug Lord Guest

    There are some self-righting keelboats that are daysailers AND wet and exciting-I don't see the two as mutually exclusive. This is a 21 footer seen on SA:
     

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  6. alan white
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    alan white Senior Member

    I'd like to see a bulb ballast on a deep foil, but set up to raise like a lifting keel for trailering purposes. An underbody cutout the body plan shape of the bulb would allow the entire keel/bulb to be brought flush with the bottom.
    This would be raised by halyard with tackle added.
    The reasoning is simple. Dealing with a very deep draft boat, not only is one spending for getting the boat in and out, but chances are the boat will (consequently) spend the whole season in one place. A new class should be easy to transport in order to attend regattas at different locations.
    Slightly more money up front, but far cheaper to own long term.


    Alan
     
  7. Cheesy
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    Cheesy Senior Member

    Sounds pretty much like this;
    http://www.seascape18.com/prvastran.htm
    Or maybe the i550

    Alan, I’m not sure why you would need a cutout in the hull for the bulb, in this size of boat your probably looking at 100-150kg, this is physically small enough that the rear cradle on the trailer just has a cutout in the middle for the bulb, in fact where I sail many of the boats will trailer launch and motor out into the harbor before fully lowering their keels. I’ve got a 23ft sport boat that I actually launch off a beach trolley like a dingy and it has an 85kg bulb. As for raising and lowering I’ve got a 4:1 tackle that can either be connected to a trap wire or the end of a windsurfer boom the straddles the keel.

    In fact in NZ/Oz almost all of the sport boats (and anything under 25ft) are usually trailer launched
     
  8. Cheesy
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    Cheesy Senior Member

    Doug, this particular design is probably not a very good example for your argument, yes it should be fast and wet but I certainly wouldn’t consider it as a ‘day sailor’ it just doesn’t have enough form stability and way too much sail area, high sheet loads etc, maybe on a really light still day, however it would be pretty ‘sticky’ and slow upwind in that case. Something like an Open 5.7 would be a better example I think.

    In terms of self righting I kind of get the impression that some people are actually implying ‘not capsizing’ ie laying over, rounding up and popping up into the wind with the sails flapping, this is definitely not the case with some of the lighter faster sport boats.

    As for quoting a design as self righting it really depends on what rule it is built to, the NZ SB rule is probably one of the less restrictive of all and from memory (maybe wrong here) it is something like 10% of the bulb mass at the hounds to hold the boat at 90deg, with this requirement its likely that the boat will not be AS self righting as people may expect, if you’ve got the kite up it will not self right and if you go past 90deg it may not either
     
  9. alan white
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    alan white Senior Member

    Cheesy, how deep for a 150 kg bulb on an 18 ft boat? Like 2m?
     
  10. Wynand N
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    Wynand N Retired Steelboatbuilder

    we are actually starting to tool up a 6 meter trailer/daysailor and it is very similar to the Melges20 in shape and concept. However my boat's transom differs quite a bit and it has a cabin for occasional over night for two.

    That said, it has a vertically retractable high aspect ratio keel with 230kg bulb on the tip. Max draft is 1.5m and retracted 0.4m draft
     
  11. Gary Baigent
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    Gary Baigent Senior Member

    5.5 day sailer

    5.5m x 2.25m, sketch rigged, freestanding wing masts, 21m2 SA, 120 kgs weight, water ballast 80 kgs.
     

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  12. Cheesy
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    Cheesy Senior Member

    The keel on the picture Doug posted is pretty much 2m but about half the mass and will only be marginally self righting, as long as you’ve got enough keel area you’re pretty much trying to minimise the amount of ballast required to fit a rule (down here anyway) most of these types of boats are faster without the bulb at all.

    For your example I would think you could have much shorter with a more beam (only 1.2m in pic) and a smaller rig, see if you can find the specs on an Elliot 5.9, they will be pretty close to what you’re talking about as well
     
  13. Gary Baigent
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    Gary Baigent Senior Member

    18foot daysailers

    "as long as you’ve got enough keel area you’re pretty much trying to minimise the amount of ballast required to fit a rule (down here anyway) most of these types of boats are faster without the bulb at all."
    Interesting comment Cheesy, going against the fashionable grain - but I'm sure you are correct.
    Another shot of my 5.5m. The assembly towards the rear is for the canting rear "sketch" mast.
     

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  14. Paulo.AS
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    Paulo.AS Junior Member

    Daysailing doesn't have to be dull, does it? ;)

    If I wanted a 18' skiff I'd buy one, the idea of this thread is to gather opinions and insights for my own project, currently in its preliminary design stages.

    Everybody's contribution is valuable

    BTW Gary, what's a sketch rig? A crossover between a sloop and a ketch?
     

  15. RHough
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    RHough Retro Dude

    I was pointing out that my perception of "Daysailer" and yours are very different. Daysailer implies a boat that is more like a J22. A small relatively stable boat with no real accommodation. A family friendly boat.

    Since there are all sorts of sailing hot rods out there, and darn few sensible daysailers I thought you were aiming at that sort of a design.

    My error.

    I wish you the best.

    R
     
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