Motoryachts Capsizing

Discussion in 'Powerboats' started by Tad, Nov 4, 2003.

  1. Tad
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    Tad Boat Designer

    Can anyone report a case of a modern motoryacht (of reasonable size) capsizing? I know the USCG has done it on the Columbia River Bar. It happens occasionally to high-speed boats, usually when they are airborne.

    Steve Dashew has made a claim that "99% of all powerboats" are unsafe. I think he is wrong. See his column

    here

    Thanks, Tad
     
  2. SailDesign
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    SailDesign Old Phart! Stay upwind..

    I think you're taking him slightly out of context, Tad. He says that "The powerboat industry must assume that there are no capsize risks, because as far as we can see, 99% of all powerboats--right up to 100,000-ton bulk ore carriers--will capsize and not recover, given the right set of circumstances. "

    That implies a set of circumstances that are very hard to achieve, and almost says "if you put sails on a powerboat, it will be unsafe", or at least that's the way I read it. Yes, any powerboat can capsize and not recover, given sufficient heeling moment. Currently the only way you are going to apply that moment is by steaming side-on to a hurricane, or being broadside to a large breaking wave.
    By the lights of his sentence above, he is right. But it sure sounds like a spin to me....

    Steve
     
  3. Willallison
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    Willallison Senior Member

    ...and to me.....
    then again - I would reckon that he's not far off the mark. You only need to take a wander down to your local marina to see that VERY few powerboats would recover from a capsize. What he's failed to mention, however, is that 99.9999 % will never venture far enough for it to become a problem
     
  4. SailDesign
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    SailDesign Old Phart! Stay upwind..

    Will,
    The problem is that what he neglects to say is that there is no reason fora powerboat to be built to come back up, since the problem of rolling one can be so large. (Note the "Can" ...)
    This gives the impression that stinkpot designers have been deluding and misleading the public for years, hence my reference to "spin".
    Steve
     
  5. Willallison
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    Willallison Senior Member

    Yes - I understood your point Steve - and I agree. My point was simply that whilst there are more and more boats appearing that look like they'd fall over if you gave them a shove (pic below - surely a case in point!:eek: ) very few people are ever likely - nor do they ever intend - to cruise offshore, let alone across oceans - so ultimate stability isn't of such enormous concern.

    To answer Tads question - I've certainly not read of any pleasure craft capsizing in recent times. You get the occaisional grossly overloaded ferry in 3rd world countries, but that seems to be about it....
     

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  6. SailDesign
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    SailDesign Old Phart! Stay upwind..

    AARRRGGGHHHHH!!!!!!! My eyes!!!

    Thanks, Will - it's always nice to have a reminder of what not to draw. ;-)
    I especially love the "radar arch" on the roof. (Yes, there is a more nautical term for it, but that boat doesn't deserve it)
    Steve "hope nobody here designed that, or I'm in trouble..."
     
  7. BrettM
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    BrettM Senior Member

    If you look closely you can see at least three boats that have been cut up and stuck together to make one smaller ahem boat.
     
  8. Tad
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    Tad Boat Designer

    Steve;

    You may be correct and I'm just putting my own spin on Mr. Dashew's words. But I took great umbrage at being told I don't care about stability. And Mr. Dashew has no body of research to back up his claim. How does he know that 99% of powerboats will capsize and not recover. In many cases, if the deckhouse remained intact, they would pop back upright like a cork. They would in fact be very unstable upside down. Well, that's making an assumption, but in some cases it will be true. I'm thinking of boats with big deckhouses and small windows, the British Nelson's, Nordhavn's, etc.

    But besides that I am trying to ascertain the risk factor, is it one in 100, or one in 10,000, or one in a million? Were are all the motoryachts that have "capsized and everyone died"? In Heavy Weather Sailing (4th ed) Peter Hayward talks about being rolled to 90 degrees or so, but the boat popped back upright.


    Thanks for your comments, Tad
     
  9. duluthboats
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    duluthboats Senior Dreamer

    Will you have to tell us the whole story, what's the beam on that baby? LOL!

    Most of the boats that I know of that went down around here have run into sonething. That is the the real hazard.

    Gary :D
     
  10. Guest

    Guest Guest

    Tad,

    Many of the current popular cabin cruisers certainly look like they could go over fairly easily, but that is no proof that they will.

    I do remember quite a few lawsuits mentioned in the Boat US monthly publication a few years ago about his very thing. There were instances of boats capsizing in fairly common circumstances especially when several crew were on the flying bridge during a routine turn. Boat US probably has records about this kind of thing.

    Tom Lathrop
     
  11. gonzo
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    gonzo Senior Member

    I agree with willallison that most powerboats are fair weather boats only. They also have more speed than a sailboat so can make it into port faster. In rough weather most of those tubs will sink, I have no doubt.
     
  12. BVI Jon
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    BVI Jon Junior Member

    Morning,

    Having dealt with at least 30-40 power boat capsizes, both in the USCG ond out, I cannot remember a single one that wasn't caused by either a shift in cargo (people, dope, food, whatever),

    or

    enough water entering the vessel from heavy weather, busted hose, etc to set-up "free surface effect", reducing stability enough to lay her over on her side.

    Occasionally they were recoverable, but only if no more water was allowed in, and either the existing water pumped-out, or shifted weight moved back to original side.

    Sorry about no specifics.

    Jon.
     
  13. gonzo
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    gonzo Senior Member

    Tad:
    There are many seaworthy powerboats being built. The trend in trawler yachts and converted lobster boats shows that many owners are concerned about seaworthiness. However, the floating condominium willalison posted is a prime example of a fair weather only boat. What do you mean of "reasonable size". If you referr to large yachts, it is a different story. The midsize designs are probably the worse.
     
  14. Tad
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    Tad Boat Designer

    Thank you everyone for your comments.



    Tom; I will get a inquiry off to Boat US today, many thanks for that link.

    BVI; Thanks for your note, the USCG (CCG as well) might have some statistics on this somewhere. I will inquire. Capsize is quite common in the commercial fleet, fishing vessels especially. But in those cases it is (almost always) caused by a combination of overloading and water getting into the vessel because of the overloading. I know of some cases of swamping, where a wave or waves come over the transom and fill the boat.

    gonzo; What I am specicifly looking for is cases of motoryachts or powerboats, say between 20' and 70', capsizing due to heavy weather. There must be some cases of this happening due to power loss or just bad management.

    Tad
     

  15. 8knots
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    8knots A little on the slow side

    The condo boats....

    I don't know of the article you all are talking about but the pic Will posted lookes like a production boat with a LOT of custom work done to it (enclosed bridge and aft enclosure) The owner got sold up the river on that one I think. He and the wife wanted to much creature comforts that could be offered in that boats available space. Looks like they went to an unscrupulus refit yard and said "We want....... here is a check" I hope they are truly coastal cruisers!
    As I have wandered the docks in Alaska I see many many boats with homebrew enclosure type things on both commercial and family style boats that make me shudder to think of whats gonna happen to that THING in a blow! Alaska will kill you quick on a good day. Let alone the family bayliner running the 55nm's to Prince William sound.
    If you had numbers on capsizes... It would be interesting to break them up by 1(stock boat) 2(modified) and see what happens.
    anyway just a thought 8Knots
     
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