best hull for short steep chop

Discussion in 'Sailboats' started by Brian Fredrik, Dec 20, 2010.

  1. Brian Fredrik
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    Brian Fredrik Junior Member

    I am looking for opinions. What sailboat characteristics (hull and rig) are best (speed and comfort) for beating into a short steep chop wave pattern. (keeping the loa at 30ish feet) My guess is that narrow with a sharp entry is good and that flat bottoms are bad. If you had to sail often in these conditions, what type of sailboat would you absolutely not want to have?
     
  2. daiquiri
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    daiquiri Engineering and Design

    How do you define "short and steep"? :)
     
  3. maarty
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    maarty Junior Member

    Hi Brian,
    Generally speaking, a boat with a heavy enough displacement and well balanced rig is going to help it maintain speed and punch through chop. The amount of freeboard is also going to factor in, as the windage of it will create drag. The sail plan also has a big impact; ability to balance, reduce sail and shake out reefs is going to be equally as important as hull shape. You want the boat sailing on its feet.

    Carl's Sailboat calculator: http://www.image-ination.com/sailcalc.html
    is an excellent site for comparing boats and getting capsize and comfort ratio data.
    I think you should use boats like the Contessa 32, Contessa 26, Alberg 29/30/37, Bristol Channel Cutter, and Frances Morris 26 as your benchmark for comparisons.

    The list of boats that you would NOT want to have is very long.
     
  4. gonzo
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    gonzo Senior Member

    Speed and comfort are mutually exclusive. For speed a light boat with a powerful rig will get you to windward fast. A multihull can be a good boat because the hulls are narrow, but the motion will be unconfortable. A deep heavy boat will have a slower motion but little speed.
     
  5. souljour2000
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    souljour2000 Senior Member

    I'm far from being an expert on this but I agree with what Gonzo said and I believe many others would as well...Speed and comfort in boats under 50 or 60 feet are fairly exclusive to each other....it's a tradeoff...speed or comfort...the lightweight boat has speed to help you outrun the storm...but if you get caught in it your going to take a beating in that flat and lightweight hull...your gonna get spanked around alot more than if you are caught out in the older heavy displacement narrower hull...you may not outrun the storm but when you get caught in it you can heave to in a heavy steep chop and ride it out below with alot more comfort than you'd have on the newer wider lightweight boat.
     
  6. MatthewDS
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    MatthewDS Senior Member

    Your description of "short and steep" chop fits my area (Southeast Alaska) pretty well.

    Popular sailboats here have full keels, highly flared hulls, heavy displacement, and are often double ended. The Fisher 37 (http://www.google.com/images?q=fisher 37) is a great example of this.

    If you want speed rather than comfort, I have no idea.
     
  7. bulk-head
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    bulk-head Junior Member

    The Best hull shape to sail in a seaway has a fine entry forward to slice thru waves with low energy loss and with the yachts weight concentrated in the middle of the boat . Full sections forward absorb wave energy...heavy ends cause the boat to hobby horse and make things even worse. Also on the wish list is high righting moment...stiff, with a low wetted surface easily driven keel so your not sailing on your ear. A big powerful rudder that allows an alert helmsman to steer the bow of the boat thru waves is also important. Modern racer cruisers by all the top designers follow this approach.

    As you can see the older Swan 46, full forward , absorbs much energy when pushing to windward in a chop
     

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  8. CatBuilder

    CatBuilder Previous Member

    The easy part of the answer is "nothing too beamy and something with a higher deadrise angle." Also, good bows like mentioned earlier.

    You'll want to slice through the chop, not slam up and over it. You need momentum (weight) as well to ensure the boat stays basically stationary in a vertical sense while going from small chop wave to small chop wave.

    I assume we're talking about lake Ontario chop. That's some pretty mean stuff compared to open ocean sailing. I've sailed it. Very steep, very tightly packed chop. It'll rattle your bones apart if you don't have a forgiving boat.

    It's similar to the Chesapeake when you get a very strong northerly wind and that terrible chop in there, for those of you know know the Chesapeake. Only difference is that winds are mostly westerly in general in that part of the USA/Canada, so our OP has some pretty serious fetch, chop and winds to work into often.
     
  9. SamSam
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    SamSam Senior Member

    What's the size of the waves you're talking about? What are you going to use the boat for and what sort of load will it carry?

    You want it to handle the worst conditions that might come up. You might beat up into the waves for awhile and then have to turn around and run for it, and I don't know how well a sharp, narrow entry will work if you're pushed from behind into the back of the wave in front. I would think you want some below waterline flotation up forward to keep it from tripping.
     
  10. MatthewDS
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    MatthewDS Senior Member

    @Brian

    My post and Bulk-head's post provided very different answers, and highlighted different assumptions about your question.

    Why are you sailing? It is for cruising/leisure or racing purposes?
     
  11. gilberj
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    gilberj Junior Member

    Short steep seas describes most near coastal waters, whether on the Great Lakes, Chesapeake, or Salish Sea. Shallow water exaggerates the condition, like the SW end of Lake Erie.
    Going to windward in a chop, I'd rather have fine ends and a moderately light displacement length ratio. I think of Herreshoffs Rozinante, or the Contessa/Folkboat mentioned above. My own Meadowlark works pretty well here as well.
    Bigger fatter deeper bodied boats tend to get a bit punchy, and if the sea gets higher, might start pitching and plunging, losing a lot of energy(boat speed)at the same time. The post above saying you seldom get speed and comfort together is not far off. I'd still rather have the fine ended boat for those conditions because I get bored trying two or three times to get over a single wave. Really the accelerations and decelerations of punching into a chop can be annoying and uncomfortable and wet..... It feels better to have less of each.
     
  12. bulk-head
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    bulk-head Junior Member

    If youre looking for a modern, well engineered, fast upwind, boat in the 30ft range the Farr 30 is a great boat. They have stood the test of time and are not so expensive these days.
     

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  13. Pierre R
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    Pierre R Senior Member

    I can see that you and I have very different ideas about chop, ride and comfort.

    In one sentence. I want inertia (high D/L), adequate sail/dsiplacement ratio (15-16), even distribution of weight across the water plane, slack bilges and a fine entry.
    Then again, what would I know about chop, I sail western Lake Erie.
     
  14. Pierre R
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    Pierre R Senior Member

    Carl's Sailboat calculator is a nice site but you need to be aware of a few pitfalls in it.

    Pittfall number one is that the displacement given on the boats is all over the map from a no load light ship condition to a fully loaded boat and everything in between. In order to compare you have to do a bit of research on the boat you want to know what load conditions you are comparing.

    The second problem is numbers are misleading. If you want to beat all the sailboats for comfort ratio and capsize ratio just put in a 2' diameter 12' long log sharpended on both ends like a pencil and hollowed out just enough for one person. A real Flintstone's boat. Use 32lb per cubic foot for the log or about 950 lbs with one person. The capsize ratio and comfort ratio cannot be beat but I will guarantee you it will capsize and not offer a good ride. Very telling about numbers we are suckered into trusting from a computer.
     

  15. Brian Fredrik
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    Brian Fredrik Junior Member

    I forgot this is essentially science...numbers. I define short chop as roughly 1 m tall and about 2 m long. I am curious for determing hull design for a future sailboat. Your opinions are much appreciated. Thank you.
     
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