Other than Crevice Corrosion problems, Stainless Steel is pretty bulletproof. The problems arise when you MIX Dissimilar metals in an electrolyte..water in this case. Doesn't need to be salt water.
Lets take ONE square inch of
surface area of carbon steel (ordinary metal parts that most metal stuff is made of)... with ONE square inch (area) of Stainless Steel, and bolt them together and immerse them in an electrolyte (water) over a period of time. The carbon steel will corrode/disolve at a
Certain rate. The SS will remain perfectly intact.
If you Increase the AREA of the stainless steel relative to the area of the carbon steel....to ..lets say TEN times the area of the carbon steel....The SS will still remain perfectly intact..BUT..The Carbon Steel will corrode/dissolve at a MASSIVELY
Increased rate
This is NOT GOOD when you consider that a chain is only as good as its weakest link.
All Carbon Steel....Galvanized....is the BEST material for a mooring...Salt OR Fresh. This is not my opinion, this is engineering fact.
APS: I admire your ingenuity and perseverance.
NB