Comparing wartime naval officer training

Which navy had the longest and least effective officer training in the world-war era?

Most were broadly comparable; Japan's system, especially for aircrew, was notably slow at producing replacements.

Programs varied and wartime needs compressed some courses, but no simple national ranking captures the whole system. The major navies were broadly comparable overall. Japan stands out for the slow replacement pipeline associated with its naval aviation training, although comparing duration alone can mislead because each navy organized instruction differently. A reliable cross-national ranking would require a dedicated study of the different programs rather than a quick comparison of course lengths.