I have a 2018 Crestliner with a 150hp Mercury 4 stroke. I've taken it out in saltwater many times since we bought it new. My problem is, even after a long freshwater rinse and detailing, I still find corrosion in the hub of the aluminum prop. My question is, do stainless steel props have this issue and is it worth the cost to upgrade? Otherwise, the aluminum prop is in great condition.