Why do you think the maps and charts from Prince Henry school were guarded so closely?

The maps and charts from Prince Henry School were likely guarded closely due to their valuable and sensitive nature, as they contained critical navigational information that could provide significant advantages in exploration and trade. During the Age of Discovery, such knowledge was a key asset for maritime nations, and safeguarding it would have been crucial to maintaining economic and strategic dominance. Additionally, the competitive nature of exploration during that period would have heightened the need for secrecy to prevent rival nations from gaining access to these insights.