Octavian, thank for the search. It really proves the point.
Yachts are high ticket, high maintenance items. In addition, hardly any yachts have been made with ferroconcrete hulls since 1980.
I used your search to show Ferro-Cement boats from 1980 to 2000. There are 35 of them. Then I searched for all hull types. There are 35,000 of them. So we are saying that 0.1% (0.001) of boats are made with concrete hulls. There are 76 boats made with PVC, so PVC has twice as many as concrete.
So what we are needing is maintenance free platforms. Examples of platforms sitting in the ocean, and how durable and long lasting they are. Can you find any other examples of a concrete platform that is 45 years?
Maybe we should look harder at normal steel hulls like bulk carriers use.