Duarte Pacheco Pereira was probably one of the first early modern Europeans to scientifically study the relationship between the tides and the phases of the moon, which played a critical importance in the course of the Battle of Cochin, and carefully took notes on the timing of the tides. Pacheco is said to have been the first to notice their connection to the moon and to establish rules for predicting the progress of tides by reference to lunar observations. He also sifted through his data to correct and improve astronomical observations (notably correcting the average daily deviation of the moon from the sun) and constructing nautical measurements to be used by future Portuguese navigators.