It is considered the most expensive Chilean movie ever made.
The writer and Director of the film is a direct descendent of the Spanish consul in the city of Iquique at the time. Iquique, where the battle takes place was then a Peruvian a Peruvian town. After the battle, the consul vouched to the Peruvian authorities for an appropriate burial of the deceased officers and sailors.
Producers, build replicas of the two principal ships that participated in the battle of Iquique. And by the time the Esmeralda had to sink they shot the replica actually sinking into the ocean.