Trivia

[prime]

Concrete is no different than any other heavy material, Leadingham explained: as long as a ship is shaped in such a way to displace the water it's floating in, it could be made of anything. Concrete ships continue being produced, he noted, "and they float just fine."

https://www.chron.com/gulf-coast/article/shipwreck-selma-galveston-history-concrete-21088324.php