USS PT-523 was a motor torpedo boat of the United States Navy, a PT boat carried as hull 523 and also written USS PT-523.
On the night of 24-25 October 1944 she was one of the motor torpedo boats on patrol in Surigao Strait. That night on the strait is the duty named for her.
Thirty-nine boats were on patrol in Surigao Strait through those hours. PT-523 was one of them, out with the other motor torpedo boats from the night of 24 October into the morning of the 25th.
In the Battle of Surigao Strait on 25 October 1944 she was in the motor torpedo boat patrol. The battle places her with that patrol on the day the action is dated.
For this hull the night of 24-25 October 1944 and the battle of 25 October are one passage: PT-523 on patrol in Surigao Strait among the thirty-nine motor torpedo boats.