are almost as big a problem as rudders.
What if a tricolour was mounted on a bearing on the mast head, with a short strut attached to the light. Tied to the strut is a thin stretchy (to accommodate mast bend) line which is attached to the now bow. When you shunt, the line is undone and reattached to the new bow, rotating the light independantly of the mast.
Could also have struts out the side of the light, and take two strings to the ww hull. Pull one to make the right side the bow, the other to make the left.
Could probably manage it with one string and some form of trigger on the mast, but I have not figured out how.
rob