Wouter,

Good points on this important technique.

So, from looking at the pictures posted in this thread I the USA vs USA one),....is the photo angle sufficient to determine what the top of the mast is doing?

One can see from the spreaders, an approximation of mast rotation, yes. I appears to be minimal mast rotation.

Plus, we can see the effect on the top 4 sail panels.

So, if there is enough visual support, which is happening....in your opinion ( or anyone who cares to venture an idea)

.....mast bend-to-lee? ( bend on minor axis)?

....or mast bend-to backwards (bend on major axis)?

regards,

Bruce
St. Croix