How does a submarine dive into the sea?

A submarine is an undersea vehicle. It uses nuclear or diesel engines for reciprocating motion and is powered by a propeller like a ship. Submarines also have an additional job to do. Surfacing when needed and diving when needed. It has an extra simple design for this job. Submarines have large sized tanks. It contains air. When the tank is empty, the submarine floats on the surface. As it fills with water, the weight of the submarine increases and it begins to sink. Watering is stopped after reaching the desired depth. Management is based on the calculation of how much water is filled in the tank and how deep the chart is prepared.