Gavin Kerr 31 foot yacht? Selecting spinnaker?

Discussion in 'Sailboats' started by DennisRB, Aug 20, 2010.

  1. DennisRB
    Joined: Sep 2004
    Posts: 1,270
    Likes: 27, Points: 48, Legacy Rep: 228
    Location: Brisbane

    DennisRB Senior Member

    Does anyone know how to get in contact with Gavin Kerr? My partner has a 31 foot yacht built and designed by him. Its fractionally rigged and I just want some numbers on the rigging so I can select a correctly sized second hand spinnaker for it. Or what other steps can I take in finding a suitable size range for a used spinnaker?

    I'm sure I could just contract a sail maker but that sort of defeats the purpose of looking for a cheap used spinnaker.

    Thanks. Dennis.
     
  2. Paul B

    Paul B Previous Member

    You need to know the hoist (ISP) and the pole length (JSP) for the spinnaker. Generally the pole is the same as the J dimension, but if the boat is underpowered you can go up by about 10 - 20%. Be careful to keep the aspect ratio reasonable.

    Take a tape measure and pull it up on the halyard and measure the ISP. The base of I should be the sheerline at the mast.

    The SL of the spinnaker should be 0.95*(ISP^2+JSP^2)^0.5 max.
    The SF and SMW should be JSP*1.8 max.

    Now seach the used sail bins for something close.
     
  3. DennisRB
    Joined: Sep 2004
    Posts: 1,270
    Likes: 27, Points: 48, Legacy Rep: 228
    Location: Brisbane

    DennisRB Senior Member

    I tired to give you rep but it says I have to share around first :p

    Good tip on the hoisting a tape up the halyard and big help in general. Now let me google some of those acronyms. :D Pole length is easy as it has a pole.
     
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