*JimH* wrote:

The SS prop has the advantage in both categories and is therefore more
efficient.

The downside is that if you hit something you will end up doing some
serious damage to your lower unit vs. an aluminum prop shedding part
of its blades.

I've come to a different conclusion after 5 decades of scraping bottoms.
The SS holds up better and does not add substantial additional risk. I
say that having hit submerged concrete at WOT while river running (even
having to repair holed lower units from impacts). If you do a LOT of
boating, SS is the way to go.

--
Skipper