I just had a look at the waxy line. Yes, it definitely failed!. The end tapered approximately to a point (eg not a cut). There was about 3 feet coming out of the middle hatch, so the line parted that distance either forward or aft of that point. The service guy wasn't available, so I couldn't get any more information.
I have now made up some 4 inch long carbon fibre "fingers" which I will bolt to the the top of the flat section of the rudder, using the existing screw plus an SS nut and bolt, and fit an SS ring to a hole at the outer end, the extra length improving the leverage. On the starboard side I will set up a bungee cord, adjustable from my seat, while on the port side I will rig a 2mm 100kg breaking strain polyester cord forward, where it can be attached to a crossbar I will fit to the tiller lever in an emergency.
This will mean that the tiller will steer the TI either through the internal control lines, or through the back-up external ones. Photos will definitely follow!
In normal circumstances, the back-up steering system will sit in the mesh pockets at the rear seat (I currently drive from the front seat), but would obviously need shortening if I moved to the back seat.
Perhaps it was because I was in the front seat, but I was basically unsuccessful in steering with a paddle despite trying lots of alternatives for almost two hours, and I will no longer venture offshore until I have rigged up an effective back-up steering system.
I would like to recommend that all of you experiment by raising your rudder in different wind strengths to find out for yourselves if you can control your Island without a rudder. Better in practice than when the excrement hits the rotary evaporative device...