How High Above Water Did the Periscope of a WW2 Fleet Submarine Fully Extend?

During the World War II era, the periscope of a fleet submarine typically extended approximately 10 to 12 feet, or about 3 to 3.7 meters, above the water's surface when fully raised. This height played a crucial role in enabling the submarine crew to observe their surroundings whilst remaining submerged, maintaining a low profile to avoid detection.

Adjusting the Periscope Depth

It is important to note that the exact height of the periscope above the water can vary based on how far under the surface the submarine is located. Periscope depth is generally a range of a few feet, with the submarine able to adjust its position to optimize the periscope's visibility. This flexibility allows the submarine to maintain its operational capabilities in various underwater conditions.

US Submarine Periscope Specifications

The length of a US submarine periscope is approximately 40 feet, however, the height above the water is not a fixed measurement but is instead determined by the running depth of the submarine. The running depth refers to how deep the submarine operates below the surface, which can vary based on mission requirements and environmental factors.

The specific design and components of a submarine's periscope can also affect its operational range. For instance, the periscope might consist solely of a focusing objective lens, or it might include additional features such as radar equipment. The conning tower of a US Gato or Balao class submarine is around 25 feet above the keel, and the top of the periscope shears (the part that extends above the water) is approximately 42–45 feet above the keel. A typical periscope depth for such a submarine is 60 feet, with radar depth measuring 40 feet.

Practical Elevation and Wave Action

When the periscope is extended, the highest point it reaches above the water surface is crucial to consider. Taking typical wave action into account, the highest point of a raised periscope is usually around 25 feet above the surface. This estimate provides a buffer against wave-induced elevation changes in the ocean. On the other hand, when a submarine surfaces, the highest point of the periscope can extend to 45 feet above the water surface.

Conclusion

The periscope of a World War II fleet submarine was meticulously designed to allow observational capabilities while maintaining operational stealth. The specific height of the periscope above the water varied based on the depth of the submarine and the environmental conditions. Understanding these details provides a clearer picture of the strategic importance of the periscope during one of the most crucial periods in naval history.