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  #1  
Old 05-05-2009, 12:06 PM
FireBeard FireBeard is offline
 
Join Date: May 2009
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Location: New Orleans, LA
Question about my cat hull

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?


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Old 05-05-2009, 04:08 PM
bill broome bill broome is offline
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get some numbers off a hobie cat- they are probably right.
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Old 05-05-2009, 04:59 PM
Chris Ostlind Chris Ostlind is offline
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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.
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  #4  
Old 05-05-2009, 05:20 PM
FireBeard FireBeard is offline
 
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Location: New Orleans, LA
Intended Use: casual sailing, will include beach landings.

Max payload 2 people + gear.
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  #5  
Old 05-05-2009, 05:44 PM
Chris Ostlind Chris Ostlind is offline
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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.
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  #6  
Old 05-05-2009, 06:13 PM
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Richard Woods Richard Woods is offline
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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
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  #7  
Old 05-05-2009, 09:06 PM
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rayaldridge rayaldridge is offline
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Just as a data point, here are the Freeship lines of a boat I'm building, which by a coincidence is a 14' cat.



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.
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  #8  
Old 05-05-2009, 09:38 PM
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lesburn1 lesburn1 is offline
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A site to refrence.

Thy to look around this site, there are a lot of good ideas.

http://www.gust.ax/gallery/f12/
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  #9  
Old 05-06-2009, 04:04 PM
FireBeard FireBeard is offline
 
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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.
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