Francesco Verusio told a hearing in Grosseto if there had been no wind the January night of the maritime mishap, "the ship would have capsized and sunk in a minute" with 4,200 people on board.
"It was the hand of God that drew the Costa Concordia towards Giglio island after the collision with the rocks at Giglio, not Capt. [Francesco] Schettino's maneuver," Verusio said.
"He had no propulsion and the rudders were locked, he was saved only by the momentum."
His remarks came on the third day of testimony at a hearing on whether to indict Schettino, who admitted making mistakes the night the Costa Concordia struck the submerged rocks and ran aground.
On Tuesday, the court heard expert testimony that Schettino had "time and room" to avoid crashing into the rock formation.
Adm. Giuseppe Cavo Dragone said Schettino "failed to react ... there was plenty of space, a huge amount of water and time to approach and take [the ship] out of danger."
Schettino is under investigation for multiple manslaughter, abandoning his post before all passengers were evacuated and failing to communicate properly with maritime authorities.
Also being investigated is his second in command and the head of the Costa Cruises fleet.