[OldMissileer]

Was this the test where a decommissioned battleship was blow vertical standing up in the water?................

No. That was Operation Crossroads-Baker, an underwater shot performed much earlier in 1946.

[Red Badger]

The Wilson cloud lifts, revealing a vertical black object, larger than ships in the foreground, which most observers believed was the upended battleship Arkansas.

http://en.wikipedia.org/wiki/Operation_Crossroads