Yanmar 3 QM 30, max propshaft speed 1300 rpm, a 1 1/4" propshaft 31" long, there is crevice corrosion on the shaft over an area of about 12" , this part is within the shaftlog and the PSS, the deepest pocket would be about 1/32 " deep, is this cause for concern. I do use an anode on the shaft. Any advice or suggestions would be appreciated.

Mike Laaper