Ship’s windows are the most important and striking feature on a ship’s side. The ship’s windows are known as portholes, shortened form of the word ‘porthole window.’ The materials used for building ship portholes are stainless steel, aluminum, brass, bronze, and iron. The glass used in the portholes is compulsorily made involving sand. Making glass is known as sand-casting; silica sand is the primary material for this process. To make the glass, a mixture of silica, lime and ash is mixed, heated and cooled until the right consistency of glass is achieved. Materials such as brass and bronze are preferred over iron and steel because iron rusts because of seawater, and steel bends after a certain period. The glass is put in a metal cover or steel frame with a shaft or screw to keep it firm. Hence, the watertight glass cover protects the ship windows from breaking or damage. Portholes have become quite trendy. One can find numerous antique maritime portholes for decoration purposes. But just because of their utility, they are still used extensively on ships worldwide.