Why Do Military Submarines Use Red Lights?

The deadliest attack submarines in the U.S. Navy thrive in the darkness of the ocean's depths, but every once in a while they need to rise to periscope depth so the crew can get a lay of the land.
The Washington Post

Admirals See Simulation of Periscope Sweep

PEARL HARBOR, Hawaii, March 9 -- The Navy court investigating the USS Greeneville's fatal wreck with a Japanese trawler today saw how difficult it may have been for officers aboard the submarine to ...
MLive

Peer out the periscope, sleep next to torpedoes on a World War II submarine

MUSKEGON, MI -- Sitting in the Muskegon Lake channel is an 82-year-old piece of World War II history. And you can sleep on it. The USS Silversides is one of the most successful submarines of World War ...
Time

World: Periscope Rescue

A U.S. submarine prowled around a Jap-held island. From the bridge her commander watched Navy planes raiding enemy installations ashore. One of the planes was hit by flak. A parachute bloomed, and the ...