Along the way, other vessels joined the fleet. On April 30, the Portuguese realized the Brazilian fleet and prepared. On May 4, 1823, shortly after sunrise, the Brazilian squadron fell on the Portuguese fleet formed in two columns, to compensate for numerical inferiority of 7 Brazilian ships against 13 Portuguese ships, Cochrane decides to cut the enemy's line by placing the ship-flagship Pedro I plow between Portuguese Princess Royal and the frigate Constitution thus involving the rear enemy before they could maneuver the forefront to help her with this numerical inferiority was compensated.