I placed the valve in the spot where I felt that I was least likely to snag it with a line. For me that was at the bottom of the mast, in front. I already had something in place to keep the jib sheets from falling down that far.

The mast base extends exactly one inch up from the bottom of the mast. That is one inch from the bottom of the mast extrusion, not from the bottom of the mast base.

GARY