Great day with Yachtmaster Examiner/Instructor Mark Lewis, who is based on the Orwell River, and Principal Instructor at Shearwater Sailing School.
My notes for future reference, diagrams by Mark:
Z Spars are upgrading me to a larger model FOC, how is that for service!
The problem is to achieve an acceptable angle, I reduced the inner tube by approximately 200mm, now just before the boox is horizontal there is no spring and the two tobes are tight together.
The mast foot fitting extend up inside the mast making it difficult lower the mast bracket further, but it could possibly be lowered by 30mm.