As an aside, Oryx is a modified Bernd Kohler design, LOA 33' Bi-Plane Junk Rig. Bernd Kohlers designs are all drawn to be built in plywood with epoxy sheathing.
The official South African Rescue web site story .....
I sail alone all the time and have been guilty of not tethering to the jack line in benign conditions; not any more though after reading this. A similar tragedy occurred a few years back to a couple sailing their yacht between Sydney and Pittwater. If I remember correctly the wife went below to sleep and woke to find her husband missing. The conditions were also benign. Hopefully we all will learn from Carly's tragic loss.