Added 11/16/2004

Does the rudder hang on the transom or does it attach to the back edge of the keel?  The reason I ask is that Columbia made two "23" models. One is the Contender and it had model designation C-23. Its rudder hangs on the keel. 

  The other is the 23T. I'm guessing that's what you need the rudder for.  It is a trailerable boat built in the '70s.  If it's the trailerable, you can get a copy of the rudder plan from:

 

     Justin Thompson

     MarineInfo & Design, Inc.

     1500 Niagara Blvd

     Lewisville, Texas 75077

     Email: columbia@sailinfo.com

     214/291-5903 facsimile

 

There is a list of all the plans he has on the Columbia Yacht Owners website http://www.columbia-yachts.com  Go to the model specifications page, click on the 23T link and then click on the link for the drawings available.  The rudder is the same as the one used on the Coronado 23 (model A23).