Albert Barnes Commentary Acts 27:35

"And when he had said this, and had taken bread, he gave thanks to God in the presence of all; and he brake it, and began to eat." — Acts 27:35 (ASV)

And gave thanks, etc. This was the usual custom among the Hebrews. See Barnes on Matthew 14:19.

Paul was among those who were not Christians. But he was not ashamed of the proper acknowledgment of God, and was not afraid to avow his dependence on him, and to express his gratitude for his mercy.