During most of WWII in the South Pacific the USN had early versions of surface radar but were developing better units all the time. The Japanese had scopes and binoculars and the most competent shipboard observers able to profile identify our ships and other combatants day and night. Their optics were unsurpassed. The Japanese had troublesome inaffective shipboard radars around 1944-45 but they were undependable so optical glasses were necessary. 

Rick