cavitation

[bec]

ok here is the deal i have been running a 28 et prop for two years and have never had any signs of wear on the blades.i was looking at the blades last night and i noticed the backside of the blades from the hub about 3/4 up the blade the edges of all three blades look like somebody took a polisher to them. they are very shiny compared to the lab finish ..and the front of the blades on the edges are doing the same thing.cavitation?:o?the only thing i have done different to my boat setup is change my torquemaster with a tooters cone to a sportmaster fatshaft.does the tip of the nosecones ride at a different height compared to each other?i am at the same engine height.i have a 28 et had for four years that finally slung a blade a few years back sitting in the shop that still looks good other than the blade cracked no shiny spots on the leading edge of it.funny thing about it though looking at the et i am running know on the backside of the blades where the shine stops 3/4 up the blades is exactly the same spot where the other et i had lost its blade.looking at purchasing me another prop and just wanted to get yalls opinion .dont want to mess up a new one.