Traditionally, by using a periscope to view optically above the surface. As periscopes are a weak point in a submarine - modern nuclear submarines use external cameras instead of periscopes.
Periscope.
A periscope is the instrument used in a submarine to see above the surface of water. It works by using mirrors to reflect light down into the submarine while allowing for observation of the surface without exposing the submarine itself.
A submarine's viewing point is called a "periscope." The periscope allows crew members to see above the water's surface while the submarine remains submerged. It typically consists of a series of mirrors and lenses that provide a clear view of the surroundings, enabling navigation and observation without exposing the submarine.
They use a periscope. See the related link for more information.
Other than the periscope, which was designed to be extended up above the surface of the water to see what's on top, there isn't really a way to look out of a naval submarine. There are no windows or the like.
Submarines can see the surface of the ocean with a periscope when they are close to the surface.
A Japanese submarine .
The instrument used in submarines to observe the surface of water is called a periscope. A periscope consists of a long tube with mirrors at each end, allowing the viewer to see objects above the water's surface while the submarine remains submerged. The periscope's mirrors reflect light from the surface down the tube to the viewer, providing a view of the surroundings without the need to surface the submarine.
A periscope is used to observe the surface from a submarine
The captain of the submarine raised the periscope to see if there's danger.
In a submarine where it stays underwater but can see on surface. Or in a war it is used in trenches to see over the top without getting shot.
The periscope is used by the submarine to look around the surface of the water, while the rest of the submarine is under water. It makes the submarine harder to find and destroy by enemy antisubmarine warfare. The periscope might be just a simple set of mirrors or it might have a "heads up display", similar to HUD found in some combat aircraft, that give the range to the target, as well as a magnifying glass that also makes the target easier to see, similar to a pair of binoculars.