[Chas H]

This is the first time I have raised any mast....

I don't want to confuse the issue, but I'd like to share some basics of mast tuning to help you understand the entire process. C&C Yachts - C&C Photo Album & Resource Center has a good mast tuning guide. You may want to use a tuning gauge later, some do some don't.
Again, my purpose is to help you see the basic principles of mast tuning.
-CH