Which of the following devices is crucial for visual navigation?

The correct choice, charts with navigational aids, is fundamental for visual navigation because they provide essential information about water depths, hazards, navigational routes, and the positioning of aids to navigation. Charts allow mariners to understand their surroundings visually, enabling them to make informed decisions while navigating. They help in identifying landmarks, buoys, and beacons, which are critical for safe passage, particularly in coastal and congested waters.

While radar systems are excellent for detecting other vessels and land features in low visibility conditions or at night, they are not solely relied upon for visual navigation, which focuses primarily on what can be seen with the naked eye. Sailing software, although valuable for various calculations and simulating routes, relies on the accuracy of underlying data like charts to function effectively. Fire extinguishers, while essential for safety on a vessel, do not contribute to the navigation process at all. Thus, charts with navigational aids are indispensable for a successful and safe navigation experience.