[Ronin]

I remember back in the early 70s there was a bunch of stories about people making boats out of concrete. Haven’t heard much about them since.

[Red Badger]

THEY MADE BOATS OF CONCRETE IN WWII!......We have one here in Ft. Walton Beach..........

[Illuminatas]

You mean like these....

My alma mater, SDSM&T.

[Bender2]

Re: I remember back in the early 70s there was a bunch of stories about people making boats out of concrete. Haven’t heard much about them since.

Gadzooks! You need to go back further to find out ships were being made of concrete way before the 1970s!

Check out A Brief History of Concrete Ships and Wikipedia Concrete Ship article.

[Vinnie]

There are sailing yachts made out of concrete.

I think a lattice is formed , then sprayed. A Gunnite type construction.

I do question the thermal insulating ability of concrete though.
I know from living in S. Fla. where most homes are CBS construction that a west facing wall got hot in the interior and stayed hot for hours after the sun set.