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51004Re: [bolger] Re: How would Mr Bolger update Cynthia J?

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  • John and Kathy Trussell
    Oct 7, 2006
      The standard approach for recovering a capsized dinghy is to put weight on the centerboard to lever the boat back on her feet. This doesn't work with leeboards. If the leeboard is on the high side, it is too high for a swimmer to reach; if it is on the low side, a swimmer can't exert much force on it. Probably the best approach is to keep a length of line fastened to the gunwale amidships. If capsize occurs, throw the line over the high side of the boat, swim around to the bottom of the boat, and use the line to try to pull the boat up (with your feet on the bottom and pulling on the line).

      Obviously a boat floating high on it's side will be easier to right than one floating low. It would be relatively simple to add a bulkhead immediately behind the seats and deck in the space for substantial added bouyancy. If the seats were made wider to meet the sides and the joint between the outer edge of the seats and the side were made watertight (with fiberglass tape set in an epoxy fillet) the seats woud also provide some bouyancy (assuming thet the boat would float high enough on her side so that the inboard edge of the seat was above water).

      To make the boat truly self righting, it is necessary to add ballast either in the form of hard ballast or water ballast. If you are going to do that, it would probably be necessary to make the curve of the bottom deeper to float the additional weight.

      Another alternative is to add a 'Birdwatcher' cabin.

      All of these modifications a) increase the amount of plywood needed, b) increase the weight of the boat (degrading performance), and c) change the concept. If you want a small, self righting boat, maybe there are better designs than Cynthia J (see PCB's Old Shoe and Supermouse designs, for his approaches).

      ----- Original Message -----
      From: captreed48
      To: bolger@yahoogroups.com
      Sent: Saturday, October 07, 2006 12:22 AM
      Subject: [bolger] Re: How would Mr Bolger update Cynthia J?

      > designed, I believe Cynthia J would, if capsized, float fairly high
      on her
      > side, supported by the cabin and the bouyancy of the mast and gaff.
      > Righting her would require a swimmer to grab the stringers on the
      bottom to
      > pull her up or, more likely, a line to parbuckle the boat up. If
      capsize is
      > a major concern,

      Well....capsize is a major concern. A friend of mine capsized his
      Cynthia J and could not get it upright. A helpful park ranger boat and
      crew couldn't either but towed the boat submerged back to the launch
      ramp. By that time my friend was very hypothermic.

      I think bouyancy tanks in each quarter or across the entire transom and
      under the seats in addition to making the cabin watertight would vastly
      improve the situation. In that case the heavier bottom would help
      right her. (Not so if the boat isn't watertight..wood floats, but not
      very high.)

      Let us know how it goes.



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