In that terrible weather in June we lost five of the nine boats moored at Bundeena.
I was very fortunate to lose only the botton half of my rudder.
Would anyone have the specifications for a Southern Cross 23 rudder? I understand the Southern Cross is similar to Sonata 7. Any ideas?

First thing to do is get a mooring somewhere else!!

This is supposed to be a SC 23. Pretty simple rudder shape. You could scale from the pic and it should be fine. Even make it a bit bigger if you suffer from weather helm.

If you are going to make one may as well see if you can improve on the original.
When I changed my rudders I used the plotter at airfoiltools.com/plotter/index to get the profile I wanted and printed it out to scale.

Thank you for the three reply. I am progressing and will let you know how it goes.