INTRODUCTION Ballast tank is a very important part of any ship or submarine, It provides vertical stability against shifting of Center Of Buoyancy , when the ship or submarine undergoes loading and unloading process or maybe affected by other dynamical factors, such as ship approaching to shallow waters. BRIEF CONCEPT OF CENTER OF BUOYANCY When a body is submerged in a liquid, It gets bombarded by the liquid molecules from all sides. The vertical upward force that is exerted by the bombardment on the body, which balances the weight of the body is known as the Buoyant force. And like the Center of Gravity, The point or center through which this force acts is called as Center of Buoyancy. HOW DOES BALLAST TANK WORK A Ships body is strengthened by stiffeners, to add stiffness that make up the ship's hull as well as inner compartments. Any type of stiffener may be Floor or Stringer has holes that allow ballast water to occupy the ship's space uniformly. The pi