G'day Michael,
In the RV plan on the page titled "Epoxying and Glassing the Spars" you mention the slot in the bottom of the mast. How does this get there and what is it for. I never came across it anywhere in the mast building instructions in the RV plan or the lug rig option. I'm guessing this has something to do with the 125mm x 9mm bolt in the materials list.
Cheers, Kev.