Did you know most of the offshore CA gambling ships did not float?
They were on huge concret blocks layed and chained to the ocean floor.
In effect that had concrete hulls.

The SS Monte Carlo: Credit Ernest Marquez:
The life of the Monte Carlo ended January 1, 1936 when she broke her anchor
chains in a terrific storm New Years Eve night. The storm washed the
concrete hulled vessel ashore. She beached on the Silver Strand near the
Hotel Del Coronado in San Diego. The waves completely wrecked the wooden
structure housing the gambling casino and washed it and all the furniture,
gambling equipment, etc. ashore. The concrete hull broke in half thus
ending any hope to float her away. The hull slowly sank into the sand and
is still there today. A storm during El Nino in 1983 uncovered her and she
has risen to the surface a couple times since then. The gambling ships were
closed for good August 1, 1939. A raid led by Earl Warren closed 4 gambling
ships on that day. The Tango and Mount Baker in Long Beach and the Rex and
Texas at Santa Monica.