Although Captain Apolinar Calvo of the "Corregidor" had prior experience navigating the mined entrance to Manila Bay (the mines had been in place since July), the Navy had changed its procedures on that day. Rather than post a gunboat near the safe channel as they had in days previous, lighted buoys were used to guide boats through. As the "Corregidor" sailed close to the island of Corregidor to pass through the channel at around 01:00, the ship was observed turning toward the electrically-controlled minefield. Some officers posted at the Army's Seaward Defense Command headquarters on the island recommended that the mines be temporarily disarmed so that the ship could pass through the minefield. A number of accounts state that Seaward Defense Commander Colonel Paul Bunker ordered that the mines be kept active.