When Alison visited on Monday she saw the rudder broken. We went today to fit a new float switch and bring the gaff home to make a new one for next year and took some pictures.
The rudder has completely sheared. It was last rebuilt shortly after we bought the boat. Everson's at Woodbridge build a new head-stock onto the existing rudder and it looks like the break is roughly at the join.
We believe the original rudder was damaged in a fire at Beaumaris during the Second World War. By 1946 it looked like this, and the shape is roughly the same as the drawings in the 1937 Yachting Monthly:
We don't know when the current rudder was fitted, but as it is GRP over a scrap wood core we think it must date to the 1960s. It is a very different shape but it worked really well.
So we now need to decide whether to go for another repair, a replacement more in keeping with the original, or something different.