What is the role of a submarine periscope?

• A. To observe above the water while remaining submerged to avoid detection.
• B. To measure depth by sonar.
• C. To deploy weapons remotely.
• D. To anchor the submarine.

Answer: (A)

A submarine periscope provides a window to observe the surface while the boat stays submerged. It’s a retractable optical system that extends above the water at shallow depth, transmitting the outside image through lenses and mirrors to an eyepiece inside the submarine. This lets a crew member scout ships, coastlines, and surface conditions without surfacing or revealing the submarine’s position. It relies on visible light and line-of-sight, so it’s most effective when the vessel is just below the surface, not deep underwater, and it doesn’t replace other sensors for navigation or detection. The periscope isn’t used to measure depth, deploy weapons, or anchor; those tasks use dedicated equipment like depth gauges, sonar, torpedo launch systems, and anchors.