Aptos, California: S.S. Palo Alto Concrete Ship

Splotchy structure at end of pier, popular with sea birds, was once a proud nautical vessel made of concrete.

Pretty cool, but prepare for it to be stinky from all the bird droppings on the dock!

In January 2017, the offshore hulk of the concrete ship S.S. Palo Alto was battered by winter storms and "king tides." The ship, an experimental post-World War I oil tanker, had been retired off a pier, and even served as a platform for an amusement park. It had become unsafe, and increasingly less recognizable as a ship. The storms broke it up further, and the adjoining public pier was also damaged. The beach is still accessible, but the pier is currently closed until repairs are made.

Noticed reference to S.S. Atlantus in your "Dementia Concretia" section. This concrete ship was moored off of Seacliff Beach in the 1930's after becoming obsolete after WWI. Ship can still be seen in its entirety, although it has deteriorated to a great degree. You could walk out onto the ship from its connecting pier as recently as last year but now it seems to be closed due to the poor condition of the hull.