Net difference between upward and downward forces acting on a submerged body. Upward forces defined by [[Archimedes Principle]] Downward force is the weight of the body *Positive buoyancy* if weight of the body is less than the upward force *Negative buoyancy* vice versa Equal buoyancy is neutrally buoyant Defined by the ratio of the body’s density to the fluid’s - [[Specific Gravity]]