Mast Bearing "Chips"
One teflon chip should easily last you a year...
We used one bearing per boat at the 16 Worlds and figured that the amount of sailing time was similar to a full year of normal use. The bearings were still in the cups and still good, but thinned out a lot.
The trick? The "Chip Keeper" that Dan Ketterman (Hobie engineer) told us about and is now standard in all mast step castings. It is a simple array of holes inside the cup. Drilled 1/8" holes (6) in a circle just inside the diameter of the chip. Shallow indemts maybe only 1/8 deep. The chips get pressed into the little indents and are virtually locked in place!