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bullrout said..EastCoastSail said..ABC footage screen grab, looks like a Mini 6.5 or similar, had a storm jib at the time.
I know several steel hulls when surveyed had pitting and less than 1mm effective thickness.

So wouldn't that be the result of inadequate maintenance and neglect? Who would take their steel hull out there if it was in that bad a state, it doesn't mean that steel is a no-go in general for construction
The majority don't know they have the defect, including once myself, my personal experience:
-know of two pre purchase steel hull surveys that picked up 1mm hull plating corrosion pits. Wasn't obvious until pointed out. The seller wasn't aware
-I was the engineer of a ship that corroded through the hull from 20 years of tank dipping weight hitting the hull under the sounding tube. The corrosion hole looked like a 10mm drill bit hole from inside out ( solved with a tapered bung by diver). I had surveyed that part of the hull two years before and missed the defect.
-personally involved in several crop and renew of aluminium workboats that have corrosion pitting to less than a mm hull plate. That was found by ultrasound, the damage location on the inside couldn't be seen visually (under diesel and under the longerons).
My point is there is no ultimate hull material, they are all a compromise.
I personally wouldn't trust a steel hulled recreational yacht over 20yrs old, unless the interior had been completely gutted and the hull inspected, ideally also by ultrasound.
For a different perspective, go to your local port, count the number of commercial and recreational ships and boats from the 1980s. Classify them as steel, wood, aluminium, fibreglass or ferro. Determine for yourself what has the longevity and likely covered the most seaworthy miles.