The holes drilled to enter light or air into the boat or ship are called portholes. Thanks to these holes, the ship can easily receive light and air. The portholes allow light to enter the ship and the porthole covers can be prevented at any time. These holes are made firmly in the form of a circular frame. Windows are made in the form of glass. These openings open to decks and decks. In this way, it is ensured that these sections also receive light and that light enters these sections. The frame of the porthole is usually metal. This results in a more robust structure. When the porthole covers are closed, the light entering the vessel may be cut off. It has a functional feature.