Sink or Swim??

Discussion in 'Multihulls' started by Richard Woods, May 5, 2009.

  1. TeddyDiver
    Joined: Dec 2007
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    Location: Finland/Norway

    TeddyDiver Gollywobbler

    Well most of the time anyway allthough having a possibility to dump some is allways there..
    It's 33' motorsailer 6.5t fully loaded, longkeel 1500kg lead +800water, gaff ketch. Got some pictures in the Gallery. For drinking water separate 2x250l tanks.
     
  2. yam_fzr
    Joined: Mar 2015
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    Location: Australia

    yam_fzr Junior Member

    Sorry about raising the dead but it seemed pointless to start a new one when correcting an issue presented as fact by a World renowned designer as the OP.

    This is incorrect as the following nomogram shows:

    Wave height nomogram

    The fetch and wind speed given the appropriate duration determine the wave height. So for a short duration squall, yes, you are correct. For a long constant blow, waves can exceed 20 feet in surprisingly low wind speed, 30 knots for about 26 hours will do it. So an F7 for just over 24 hours gets those wave heights.
    Likewise, 4 hours in 80 knots will get you 20 footers.
    Some of the more interesting aspects to this are in the trade winds. If they are blowing a bit higher than normal, say 26 knots then it won't take long to get 20 footers if the wind picks up to say 40 knots , it's about 12 hours.
     

  3. ThomD
    Joined: Mar 2009
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    Location: TO

    ThomD Senior Member

    As far as the unsinkable mono is concerned it is as much as anything confirmation that the regulators think as the multi designer, that not augering into the ocean floor is a good idea. But that said there are different degrees of floatation in a storm a multi can remain high in the water with liveability, I just don't see how a mono with aggressive sailing capacity can flood and float, and remain liveable, and with modern communications that may not be the issue it once was.
     
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