My neibor has a ferro cement boat:
It is ugly as the sin with rough sides and rust streaks all over it.
Seems that the cement is absorbing water which get to the chicken wire used for re-inforcement, the wire corrodes then swells out and cracks the cement, more water gets in, etc....
(Granted, the boat is probably amateur built and in the cheapest possible way: The masts are wood and they are rotting away, the guy keeps scraping the rot away every year and stuffs bondo in the voids. The anchors are home made and the bilge pump float switch is from the innards of a toilet tank...Not making this up folks, the whole thing is a disaster.)
From what I have seen and heard over the years, would not own a cement boat even if given one for free....
