Why are most boats so narrow?

Discussion in 'Boat Design' started by CaptainDaniel, Sep 14, 2009.

  1. CaptainDaniel
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    CaptainDaniel Junior Member

    I have looked at several sail boats recently and found that most of them were extremely narrow. I understand that this makes them faster. But assuming I don't care about being fast would a wider hull have any other disadvantages? I was thinking of a wider "belly" for roomy cabins below and going a little narrower at the top. That should keep the center of gravity low, less change of flipping over?
     
  2. PAR
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    PAR Yacht Designer/Builder

    If anything boats got beamer across several generations and now seemed to have settled down to the current, wide butted concessions we now have. Are there a few specific designs you find narrow?

    Typical disadvantages to beamy hulls are weight, drag, excessive fuel use, poor handling and increased build cost.
     
  3. CaptainDaniel
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    CaptainDaniel Junior Member

    My own boat for example, 52 feet long, but barely 8 feet wide. I personally don't care for speed. To me it's more important to have plenty of living space. So I was just wondering why boats aren't wider. I am thinking sail boats only, so I have no concerns about fuel.
     
  4. peter radclyffe
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    peter radclyffe Senior Member

    have you looked at tad roberts designs or the galleries
     
  5. marshmat
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    marshmat Senior Member

    I can't think of many 52-footers that have only an 8' beam. 12' would be pretty slender in this length, many production 52-footers are 14-16' wide.

    The recent trend has certainly been towards wider hulls, especially wider sterns, but also shallower hulls with fin keels taking the place of deeper hulls with long keels.

    If you're looking for lots of volume down below, maybe something like an oversize Nonsuch would suit? Or a Dutch botter? On the other hand, if speed isn't terribly important but square footage is paramount, the Caribbean/Mediterranean charter cat ("condomaran") is pretty hard to beat....
     
  6. PAR
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    PAR Yacht Designer/Builder

    I'd have to agree Matt, hull forms have been fairly fat for some time and 8 foot wide, 52' yachts are quite rare, which makes me wonder if his boat has lengthy overhangs and actually is a 35' boat with graceful stem and stern profiles or just an odd, old design, probably British.

    Daniel, hit a local boat show and have a look at the average beam on most yachts. I think you'll find yours isn't the norm, but the exception. What design do you own?
     
  7. kmartyr
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    kmartyr New Member

    I too was wondering the same thing. I noticed that especially with older boats the boats were much narrower and (at least what I've heard) have deeper keels. I'm not really certain why this is but I have a few speculations.

    Firstly I just returned from a day sail in the ocean on a rather narrow 28 footer. One of the things I noticed was it seemed to float right over the waves rather than being tossed about by them. It may have just been the conditions of the day which made it feel so different but it does seem possible that less beamy boats perform better in high seas.

    What I believe is more likely is that it has to do with tradition. Nearly all the fully wooden boats I saw were very narrow. I'm speculating again, but I believe that wooden boats are less buoyant and as a result sit lower in the water. Having more width therefor means more drag. Perhaps as boat materials became lighter and it became more obvious that some people preferred cruising yachts over racing yachts the designs changed.

    So as far as disadvantages of beamy boats I think beside the usual worse speed, handling, I think it makes them harder to handle in ocean sailing. (rolling more with waves)
     
  8. alan white
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    alan white Senior Member

    It's very surprising to hear about a 52 foot sailboat with an 8 ft beam that is owned by a person who is unaware his boat is extremely unusual. Sure, such narrow boats have been built. A boat like that would either be extremely light and flat-bottomed and carry a low aspect rig (Bolger might have designed such a boat to prove a point), or it would be very heavily ballasted and sail on her ear (British plank-on-edge cutters of the nineteenth century come to mind)--- if it were to perform at all.

    Do you have a photo?
     
  9. uncleralph
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    uncleralph Junior Member

  10. CaptainDaniel
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    CaptainDaniel Junior Member

    My boat is a one of a kind and definitely not the norm. My question was more of a general nature, wondering if there were any major disadvantages with a wider hull. I am not talking about any boat in particular, just a simple design question.
     
  11. PAR
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    PAR Yacht Designer/Builder

    I bet it draws a lot and was intended to be towed overland.
     
  12. Ela.S
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    Ela.S New Member

    if you want to make it wider the resistance will increase in the boat because of its wider shape in the front
     

  13. Ela.S
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    Ela.S New Member

    if the ship get wider shape the resistance will increase that make you to supply more energy to move your ship
     
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