ferro-cement wasn’t expected to last long..................
Maybe that's why my folks tried to get me to wear a ferrocement life jacket. "It floats", they said. "Rock solid".
True, but the technique could (and still is) used today. Substitute the re-bar and add the supplements and you have a longer lasting concrete ship. Perhaps long enough to make it viable for a commercial vessel or a home hobbyist???
Maybe for my 49’ dream boat )(https://www.boatdesigns.com/49-Klondike-cruising-trawler-yacht/products/400/
or
https://hartley-boats.com/product/tahitian-fisherman-45-50/