Looking for Catrigged boat design ~20 foot

Discussion in 'Boat Design' started by tpdavis, Nov 29, 2010.

  1. tpdavis
    Joined: Sep 2004
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    Location: Benicia, CA

    tpdavis Junior Member

    After sailing the heck out of a 24 ft trimaran for a decade, I've sold it and am thinking of designing/building my own boat after I retire next year.

    Monohull construction this time. I'd like to sorta make a Wyliecat 17 only 3 feet longer with a little cabin.

    A starting design questions. If I take a sloop sportboat design (such as the i550) and change it to a catrig...do I have to think about relocating the keel in order to keep the boat balanced? I think building an i550 is within my skill set (stitch and glue), so it gives me a basic "starting point".

    That being said, if anyone knows of a catrigged boat that already meets my design needs, please point me to it. Thanks in advance
     
  2. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    If you have to ask this question, you haven't enough understanding of the principles involved to "design" your own boat (no disrespect intended). You'd be best advised to search for a 20' cat rig. Are you interested in a traditionally shaped cat or something else entirety? The traditional cat will have a gaff or leg 'o mutton rig, it'll be quite beamy, with all sorts of interior volume available and a jaunty old school spring in her sheer. On the other hand maybe you want a 20' Laser like craft that's really only good for one thing, going fast, possibly something in between?
     
  3. michael pierzga
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    michael pierzga Senior Member

    You might look at Herreshoff's "Coquina" for inspiration...a beautiful speedster. That little mizzen mast would make a great foundation for a cockpit tent on a mini cruiser. You should be able to play around with the size, concept and sport it up with a headroom generating wishbone boomed Wylie rig. Cat boats make great cruisers because they get the mast and bulkheads out of the living room.

    http://www.dhylanboats.com/plans/coquina_study_plans.pdf
     

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  4. tpdavis
    Joined: Sep 2004
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    Location: Benicia, CA

    tpdavis Junior Member

    Well, Since the COE of the sloop sailplan is between the jib and mainsail COE's which ends up slightly in front of the mast usually and the COE of a wishbone catrig is aft of the mast some--and given that the mainsail is larger which brings the COE even further back...I was figuring it would be close to a "wash". But if you have some specific method to calculate actual lead, I'm listening.

    I do recognize that I don't design boats for a living...which is why I want to buy a plan, but haven't found one which is why I posted in the first place.

    I do want a race boat capable of being raced single handed and eligible to participate in PHRF racing in San Francisco Bay. That means it must be at least 20 feet long and carry at least 300#s balast (If I remember correctly) and it should have a cabin of some sort. A planing hull form is needed which is why I'm looking at the i550 as a "starting solution". My desired PHRF rating is 99 given average wind in SF Bay of 15 kts during race season.
     
  5. cardsinplay
    Joined: Oct 2010
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    Location: Camp Plasma

    cardsinplay da Vinci Group

    If the Benicia location is correct, then make a call to Jim Antrim. http://www.antrimdesign.com/ He's right near you in El Sobrante, is a very experienced sailor in the Bay Area and already knows a lot about the rig on the Wylie boats.

    If he has the time, he can help you with your interest in the i550 as a starting point and what it might take to make it work, if it can work. Jim's skills and experience are of the highest order.
     
  6. michael pierzga
    Joined: Dec 2008
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    michael pierzga Senior Member

    I misunderstod...thought you were after a speedy little cruiser...You want a regatta boat. With a Wylie Rig. You know those wylie Rigs are so unique , and unique to the west coast, that I know nothing of them. The only one Ive ever seen was Planet Ocean. The rig is fast. I sailed a free standing cat rig years ago and she was quick. Your choice of 550 might also be smart if you have some 550's in your area...fast tune up for your rig against known competition. You really should carefully examine the Wylie boats. The hull design. I have feeling that they carry more hull volume forward because the rig is forward. Same with the lateral resistance. Do you have any in your area ?
     
  7. tpdavis
    Joined: Sep 2004
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    Location: Benicia, CA

    tpdavis Junior Member

    Wylie boats

    There are a few wyliecats in SF Bay, but the ones I know are 30 footers. All have keels for lateral resistance as does his wyliecat 17 design (a whopping 400# plus in a 17 foot boat). All of them seem to be fast for their length but they do not point as well as a sloop in normal winds. I contacted Tom Wylie about the availability of his wyliecat 17, but he needs a "production run" minimum of 5 boats. Also, I'd really prefer a boat 20 ft long with a little cabin so I am PHRF racing legal.

    There are 4 i550s in construction in SF Bay, but I have not (yet) been able to contact the guys who are building them. An i550 is half meter short and carries too little ballast to be legal, but I just may make a sloop if I can't find what I want.

    I'm in no rush and just starting on my quest. Looking at available resources and suggestions.
     

  8. michael pierzga
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    Location: spain

    michael pierzga Senior Member

    Makes no difference the size of the Wyliecat...the design cues will be there. Be good to closely observe the underwater details. Can you have a PHRF design rated before build ? Is it possible to refit a J 22 or melges 24 ? Must be some cheap hulls around. Not long ago I saw a J22 go to the scrap heap after it fell off a trailer. No good for one design anymore, but plenty good for a little wylicat speedster conversion .
     
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