Replies

Ferro cement boats have worked very well for their intended design, cheap and fast to build, they helped carry a lot of supplies for our military. Started in WW1 and continued in WW2. The fact that they are still around show just how durable they can be.

Now, if we were to use more modern tech, say fiber glass rods instead of steel, flexible mesh over the rods, fiber reinforced flexible concrete, coated with Grancrete or epoxy and then painted, you would a very sturdy ship that was a lot less expensive than a steel one. And while I have not run the math, with light weight concrete, you could be lighter than steel.

Might even be possible to build a boat with AAC.

You might want to re-think the coating. The enthusiasts claim that concrete is one of the few materials that does not rapidly deteriorate from exposure to salt water.

A very wealthy friend of my parents had lots of large yachts over the years. I recall he had one built out of concrete out of some place in Florida. I was just a kid at the time and wondered how that worked.

I guess it worked out okay. After he used it for some years he donated it to the local university and they do oceanography with it! (Or - that's what they say, but maybe it is really for the University president's shin-digs).