When at periscope depth, they look through the periscope. It is a prism arrangement that allows good vision around the area. It also provided for gauging distances with a built in range finder.
Periscopes allow a submarine, when submerged at a shallow depth, to search visually for nearby targets and threats on the surface of the water and in the air. When not in use, a submarine's periscope retracts into the hull.
Don't knowNo ideaHave no clue
No
The top of the periscope has a prism that reflects the light to the observers prism. The object the top prism is pointed at is seen at the bottom one.
When the submarine is upto 20 meters from the surface they use a periscope which is simply 2 pieces of glass at 45 degrees to each other. similar to the periscope used to view from a trench by the army.
The submarine
The captain of the submarine raised the periscope to see if there's danger.
The submarine's periscope and radar mast are damaged.
Periscope
red
Periscope.