Question about my cat hull

Discussion in 'Multihulls' started by FireBeard, May 5, 2009.

  1. FireBeard
    Joined: May 2009
    Posts: 3
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: New Orleans, LA

    FireBeard New Member

    Hello!

    I'll keep the intro short. I've taken it to my head that i want to design a small two person catamaran 14' long with an 8' beam. This cat is to be used in a inland lake here (lake Pontchartrain). I've done a bit of research and decided deep V asymmetrical hulls is the way to go considering what i want the craft to do.

    The question I have relates to the taper of the hull. As you can see currently the hull tapers off a bit after you hit the widest/deepest point (currently 13” wide, 15” deep, and the angle of the V is 28deg.). So my question is should I use that widest point all the way back and not taper the ends? Also, should my V be much deeper?


    [​IMG]
     
  2. bill broome
    Joined: Jul 2008
    Posts: 102
    Likes: 2, Points: 0, Legacy Rep: 48
    Location: sydney

    bill broome Senior Member

    get some numbers off a hobie cat- they are probably right.
     
  3. Chris Ostlind

    Chris Ostlind Previous Member

    So, what is the intended use of this boat?

    How much do you want to carry?

    That kind of stuff will determine if the hulls are going to work for you.
     
  4. FireBeard
    Joined: May 2009
    Posts: 3
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: New Orleans, LA

    FireBeard New Member

    Intended Use: casual sailing, will include beach landings.

    Max payload 2 people + gear.
     
  5. Chris Ostlind

    Chris Ostlind Previous Member

    Yep, the original Hobie 14 is a good place for you to start for size and shape. Just add some volume to handle the two persons and their gear thing and reduce the sail area so that it resides somewhere between the cat rig at 118 sq. ft. and the Turbo version at 146 sq. ft. and you should be able to get 'er done.

    I guess you know that a used H14 in decent shape will set you back about $700-800 bucks, or so?

    It'd be real nice if you gave the hulls more volume forward to help resist the pitchpole tendency of the Hobie banana shapes, but that's your call.

    Anyway, have fun.
     
  6. Richard Woods
    Joined: Jun 2006
    Posts: 2,207
    Likes: 162, Points: 63, Legacy Rep: 1244
    Location: Back full time in the UK

    Richard Woods Woods Designs

    14ft beach cats aren't good load carriers. The Hobie 14 was a singlehander after all.

    So you may be better to go for a symmetrical hull so you can carry two people and gear.

    I'm sure you have already looked at my 14ft Pixie beach cat design and the youtube video of it sailing with two adults and also with two children. One of the Pixie plan building sheets is available as a free download (see link on my home page). It may help to give you ideas.

    As Chris says/implies I also suggest that you look for a second hand beach cat. Even if you build your own hulls getting a used rig will save you a lot of money.

    Good luck with your project

    Richard Woods of Woods Designs

    www.sailingcatamarans.com
     
  7. rayaldridge
    Joined: Jun 2006
    Posts: 581
    Likes: 26, Points: 0, Legacy Rep: 322
    Location: USA

    rayaldridge Senior Member

    Just as a data point, here are the Freeship lines of a boat I'm building, which by a coincidence is a 14' cat.

    [​IMG]

    You'll notice a couple of differences from your lines. One is the fuller lines aft. This helps a lot with pitching, in my opinion.

    The other big difference is that mine are dory-like hulls. I think you may find it difficult to get sufficient displacement for two people and a cooler out of deep V hulls, without making them pretty deep and consequently draggy.
     
  8. lesburn1
    Joined: Oct 2007
    Posts: 25
    Likes: 3, Points: 0, Legacy Rep: 59
    Location: 40:09:01.3 - 75:07:29.5

    lesburn1 Junior Member


  9. FireBeard
    Joined: May 2009
    Posts: 3
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: New Orleans, LA

    FireBeard New Member

    Thank you everyone, i got some advice from a professor at my school and along with your advice am changing the design (those were with really zero knowledge, now i have next to zero, ha). i'll post something up when i have it.
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.